Before Season 1
When the idea of destruction came into existence, Plagg came into existence. He traveled along with the other kwamis through the universe until a mage created his Miraculous.
However, Plagg was responsible for multiple disastrous events in the past when he used his powers without his owners, such as killing the dinosaurs, sinking Atlantis, and (in a more modern event) toppled the tower of Pisa. He said that he simply didn't see the tower of Pisa when he flew into it and had too much cheese in Atlantis, but did admit he went a bit overboard with the dinosaurs.
At one point, Plagg met the genie of the lamp and learned how to play the piano, he currently resides with Adrien in his mansion in Paris, France.Ladybug & Cat Noir", Adrien opened the box that held the Cat Miraculous, releasing Plagg. He greeted Adrien then flew around his room, searching for food until Adrien caught him. Then explained to Adrien what he was (a kwami), the powers he granted (Cataclysm), the duty that was given to him (stopping the akuma and akumatized villains), and how Adrien would be able to transform. He emphasized that Adrien could not tell anyone about his existence. Before he could finish telling Adrien about his powers, they transformed into Cat Noir. Together, with the help of Ladybug, they took down Stoneheart. However, because Ladybug did not capture the akuma, it multiplied and spread, creating more Stonehearts. Plagg explained to a disheartened Adrien that he did not have the power to purify the akuma and that only Ladybug could do it. He then went back to eating Camembert.
In "Stoneheart", Plagg escaped with Adrien to Collège Françoise Dupont where he hid in Adrien's shirt until Stoneheart reappeared. Adrien and Plagg transformed into Cat Noir and went after the Stonehearts. With the help of a parachute and Ladybug, they took down Stoneheart again. The next day in the rain, he called Marinette "Adrien's girlfriend."
In "The Bubbler", Plagg started off the day by gifting Adrien a piece of Camembert for his birthday, but Adrien didn't want it, so he ate it. At lunchtime, Plagg convinced Adrien to not fight Nino--who had been transformed into Bubbler--and to party instead. When Ladybug landed at the Agreste mansion, Plagg danced until he and Adrien transformed into Cat Noir. They and Ladybug were bubbled, freed with Cat Noir's Cataclysm. Together with Ladybug's help, they defeated Bubbler.
In "Mr. Pigeon", Plagg and Adrien transformed into Cat Noir to help take down Mr. Pigeon. When they were captured by pigeons with Ladybug, Cat Noir used Cataclysm to escape into Le Grand Paris. Adrien detransformed in one of the hotel suites and Plagg complained, saying he was tired and his body ached. After devouring a wheel of Camembert, they transformed back into Cat Noir and followed the pigeons to the Grand Palais. By turning Mr. Pigeon's pigeons against him with a bag of popcorn, they defeated him with time to spare before the design competition.
In "Stormy Weather", Plagg hid in one of the containers at Adrien's photoshoot until Adrien enticed him out of hiding with a slice of Camembert. Because of Stormy Weather terrorizing people in the park, they transformed into Cat Noir. Ladybug and Cat Noir chased Stormy Weather across Paris, cornering her on the KIDZ+ studio roof. One smartly placed Cataclysm on a billboard and one captured akuma later, Ladybug and Cat Noir saved the day. Adrien detransformed and he and Plagg returned to the earlier photoshoot.
In "Timebreaker", Plagg went with Adrien to the Trocadéro to watch Kim's and Alix's race. When Alix was akumatized into Timebreaker, they transformed into Cat Noir and tried to help Ladybug. Unfortunately, they were erased from the timeline while protecting Ladybug. Back in the past, Cat Noir helped the two Ladybugs defeat the two Timebreakers.In "Copycat", Plagg was eating Camembert in Adrien's bag on his cellphone while Adrien was at fencing practice. When Adrien opened his locker, Plagg told him about the new message on his phone and then they transformed into Cat Noir to go to the statue ceremony. Afterwards, they went back to the school and detransformed after grabbed his bag they went home. However, they immediately returned to the school because Adrien's phone was missing. (Adrien blamed Plagg, but swore he didn't eat it.) On the way, they saw another Cat Noir stealing the Mona Lisa. They transformed once again and hurried over to the Louvre but were captured by the police. They escaped through the subway system and detransformed. Plagg guessed the thief was akumatized and Adrien agreed. He then accused Adrien of being jealous, but Adrien ignored him. They transformed again and went to Théo's studio where Cat Noir was captured by Copycat. Ladybug arrived and freed Cat Noir with Copycat's Cataclysm. Using a spoon, Ladybug and Cat Noir defeated Copycat and returned the city (and the Mona Lisa) to normal. In "The Pharaoh", Plagg was eating cheese and ignoring Adrien's attempts at discussing whether Ladybug went to his school and that cheese is better than girls. When Adrien saw Alya's new livestream, Plagg was impressed with the Pharaoh's face changes but they immediately transformed into Cat Noir and went to the Louvre. Arriving just as the Pharaoh was trying to leave. Before they could land a hit, Cat Noir was thrown into a sarcophagus. The Pharaoh escaped with Alya while Ladybug freed Cat Noir. They were still trapped in the room and used Cataclysm to break the bars of the exhibit resulting in them detransforming. While fueling up, Plagg asked Adrien if the spell was going to work before transforming again and freed Ladybug from a time-shifting bubble. Cat Noir then distracted all the mummies and gave Ladybug time to save Alya. Once the mummies were trapped in a bus. After Ladybug saved Alya and the city, they went home.
In "Lady Wifi", Plagg and Adrien transformed into Cat Noir and helped Ladybug defeat the villain. The next day after Adrien learned about Alya's theory of Chloé being Ladybug, Plagg teased Adrien for being in love with her. Despite that they transformed into Cat Noir heading towards the Le Grand Paris to stakeout Chloé's room with Ladybug. They entered when Lady Wifi appeared, knowing the source of her power they tried to trap her in the basement, but were led to Lady Wifi's trap in the hotel's restaurant. While trapped in the kitchen's freezer, the impact of the throw was enough to force the Cat Miraculous off Adrien's finger causing Plagg to come out. But he couldn't help find the ring because it was too cold and when it is found they retransformed. Following Ladybug's plan to defeat Lady Wifi, Cat Noir destroyed the WiFi antenna above the hotel, thus cutting her powers off. Ladybug appeared, helped defeat Lady Wifi and return the city to normal. Detransforming and being so close to Ladybug, Plagg thought Adrien was crazy since he didn't look to see who she really was. Plagg didn't understand humans and they went home for the night.
In "The Evillustrator", Plagg was with Adrien when he went to the library to research his group's particle physics presentation. When Chloé was attacked by several berets and a hairdryer, Adrien and Plagg transformed into Cat Noir. They helped Ladybug take down the hairdryer and tried to go after the villain, but he escaped. Instead, Ladybug and Cat Noir went to Le Grand Paris to investigate why the Evillustrator was after her. After a while Cat Noir was left behind to guard Chloé. Until the hero got a call from Ladybug about the Evillustrator's crush on Marinette and left Chloé in order to guard Marinette on her date with him. The date wasn't successful when Cat Noir boarded Evillustrator's boat. After saving Marinette from the sinking ship, Cat Noir chased after Evillustrator and went back to Le Grand Paris to save Chloé. Meeting with Ladybug in Chloé's room and together, they took down the Evillustrator. The next day, Plagg went to school with Adrien.
In "Rogercop", during Career Day presentations at school when Adrien was sad that his father wasn't coming, Plagg did his best to comfort him. Then, during presentations he saw Chloe put a box in her bag and quickly thought it was Camembert and left to eat it. But when looking inside he was disappointed that it wasn't but a shiny bracelet and started to play with it. However, thanks to an accident the bracelet gets stuck on Plagg's head and rolled out of Chloe's bag to Adrien's feet. Outside of the classroom Adrien wanted an explanation because of the predicament they're in; meanwhile they tried to get the bracelet off but to no avail and when Plagg said that he thought the bracelet was a box of cheese but was berated by Adrien for always thinking with his stomach. When Rogercop attacks Adrien attempted to transform but the kwami warns him if the bracelet gets absorbed his powers will be damaged. But thanks to some quick thinking Plagg gets free and they transform. Then, Cat Noir and Ladybug fight and follow Rogercop to City Hall. By nightfall Cat Noir distracts the guards so Ladybug could get inside and after the guards were finished the cat joined her. Together using Cataclysm to trap the villain they defeated Rogercop.
In "Dark Cupid", while in Adrien's room, Plagg could care less about Ladybug's identity while commenting that Adrien knows nothing about her. But he counters back saying Plagg knows nothing about love, then hears Adrien say that he'll confess his love to Ladybug and they transform into Cat Noir. Once Ladybug is found Cat Noir tries in vain to tell her his feelings but gets struck by a hate arrow protecting her. While being under the affect of Dark Cupid's arrow Cat Noir teams up with Dark Cupid and they both fight against Ladybug, once she realizes that only love can save Cat Noir. Once the cat was free and with a Cataclysm, Dark Cupid was defeated. Returning home, Plagg laughed at how cruel Adrien was being to Ladybug in an effort to cheer him up Plagg says that he has thousands of other fans to choose from and tosses a card. Then, heard that someone answered Adrien's poem he concludes that someone who writes as sappy as Adrien must be his soulmate and when he believes that it might have come from Ladybug, Plagg wasn't convinced.
In "Horrificator", when everyone begins to notice that students are beginning to disappear, during the making of a monster movieknowing there's an akumatized victim around Plagg and Adrien transform into Cat Noir. Who meets up with Ladybug and the other students while fighting the villain keeps taking more students one by one and as the duo try to fight it they find out that the villain draws it's power from fear. They all follow Horrificator to the maintenance room to find the other students trapped in pods but can't break them open. Using a pair of guitar strings and following Ladybug's lead Cat Noir and everyone were able to calm Horrificator down, purify the akuma and freed everyone from the school.
In "Darkblade", after successful mission Cat Noir de-transforms and Plagg went to school with Adrien. After that he comments on the medieval madness Adrien's akumatized teacher was whiping up and they transform into Cat Noir. The cat tries his best to fight off Darkblade but is beaten by the villain, then outnumbered and does a pretend trust fall but hears the knights heading for City Hall. Once there the hero fights the knights in a rematch but doesn't find it easy until getting rescued by Ladybug while fighting the knights they notice that they are trying to get to the flag. While fighting Darkblade to the top of the building the villain manages to get his banner, but they were both was able to stop Darkblade's conquest and return everything to normal. The next day, Plagg went to school with Adrien.
In "The Mime", Plagg was going with Adrien to watch a mime performance until they're attacked by The Mime. Once the two got to safety Plagg told Adrien that they were supposed to be spectators not performers before transforming into Cat Noir. Then, joined Ladybug who was fighting The Mime but was cut short when the villain puts them in a cage; Cat Noir tried to ram the bars but they disappear before he could. They follow The Mime who was after a theater troupe bus while Ladybug gets everyone to safety Cat Noir distracts the villain the fight continues until the hero gets pinned and was quickly saved by Ladybug. Using a shoe box and villain's powers against him they were able to capture the akuma and return everything to normal. Then, Plagg attends the performance with Adrien before returning home.
In "Princess Fragrance", soon after dealing with another villain Plagg returned home with Adrien. From watching the television broadcast Princess Fragrance attacked Prince Ali during the event. Before transforming Plagg is found in a trash can still eating and once done they transformed. Once Cat Noir makes it to the event the hero quickly gets into with the villain and throws her into the kitchen, seeing that the prince is in danger Cat Noir evacuates everyone from the hotel and believes it's best to get the prince out of Paris. But before that can happen Cat Noir and everyone else gets affected by the villain's perfume becoming one of her servants. Soon Ladybug arrives and Cat Noir goes to fight her seeing the boat Cat Noir lands on it with Ladybug and moved in to use Catalysm on the heroine but Ladybug trips the cat and uses it on the fireworks control box and after that the hero gets tossed into the river. After Ladybug returns everything to normal Cat Noir is licking himself and wonders where Ladybug is.
In "Animan", Plagg followed Adrien to the zoo who was helping Nino manage a date with Marinette and enjoyed listening in on their conversation. But when Animan and the animals he freed from their cages attack Plagg helps Adrien transform into Cat Noir and quickly joins Ladybug. Despite their efforts on trying to stop Animan the villain escapes and the animals run amok in the city, knowing that the villain is after Kim the two spot them on the bridge and when Animan gets away a second time Cat Noir places a tracker on the boy. They follow him the bakery and bait Animan into a trap but when he turns into a panther it causes the duo to run into a nearby bus and using Catalysm they trapped him. Which almost works until the villain transforms into a T-Rex. While Cat Noir managed to distract him, Ladybug restrained him and doing so allowed the heroine to capture the akuma returning everything to normal. Seeing that the cat was almost out of time the hero leaps off to destransform.
In "Simon Says", Plagg went with Adrien to the tv studio who is showing support for Nino who entered in a constant but the show was cut short when Simon Says attacks and they transform into Cat Noir. The hero tried to fight the gorilla but gets restrained until Cat Noir gets loose pushing the guard into an elevator and using Catalysm to trap him. Then, is met upon by Ladybug and Nino who's looking for Adrien, seeing how worried Nino was Cat Noir found a place to detransform and Plagg hid in Adrien's jacket and they all head to the Agreste Mansion.
Once there and coming up with a quick excuse Plagg comes out hearing Adrien say that his father never listens to him before transforming again. Despite putting up a fight Simon Says' army breaks inside needing to leave Ladybug looked for Adrien leading to Cat Noir detransforming for a second time, after Adrien is secured Plagg asked him about the sweet moment he and Ladybug had. Transforming for the third time the duo followed Simon Says back to the tv studio with a regular yo-yo and a Catalysm destroying the villain's cards they saved Gabriel Agreste. After the ordeal, Plagg saw Gabriel give Adrien a hug before spotting the boy's ring and when his father leaves he felt bad for him. The next day, when Nino gets another to chance to perform he asks for Ladybug and Cat Noir to appear with that they transform and head back to the studio.
In "Pixelator", during job experience day at the Le Grand Paris Plagg went with Adrien and things went well that's until Pixelator attacks. They both get pixelated into another dimension with Chloe needing a place to transform Plagg wasn't in much of a rush but quickly agreed if Adrien could him some cheese. Once they're freed Plagg quickly realizes that someone as been akumatizied and they transform. While trying to battle Pixelator Cat Noir was pixelated into the dimension again but uses Cataclysm to get free then quickly assisting Ladybug. They were able to stop Pixelator's photo spree.
In "Guitar Villain", when Jagged Stone got akumatizied into Guitar Villain; Plagg and Adrien transform into Cat Noir. Quickly meeting up with Ladybug they discover that he is after XY and head off to the tv studio to protect him but the villain quickly catches him and the duo head to the Eiffel Tower. Once there using Cataclysm for protection despite it failing they manage to stop Guitar Villain's performance and save XY.
In "Kung Food", Plagg came with Adrien to Marinette's house who needed a translator to speak with her great-uncle Wang Cheng who was coming to Paris. Then, head to the Le Grand Paris for a contest but thanks to Chloe's sabotage Wang Cheng gets akumatized into Kung Food. He asks Adrien if he picked up any cheese before transforming. Meeting up with Ladybug they battle Ku Food's minions along their way to the top of building and once there using Cataclysm on his bag they saved Chloe, Marinette's uncle and returned the hotel to normal.
In "Gamer", Plagg was with Adrien at the park when Gamer attacks they discover that he's after Marinette and they transform into Cat Noir. After she was safe Cat Noir meets up with Ladybug, needing a place to fight him with minimal damage to the city they went to the stadium. Still outmatched and out-sized a Cataclysm was used to destroy Gamer's robot but was instantly respawned. Using a robot of their own the heroes were able to beat Gamer in a showdown and saved Max.
In "Reflekta", Plagg went to school with Adrien for class picture day but when Juleka got akumatized into Reflekta they transform into Cat Noir. After a brief scuffle with her, Cat Noir attempted to use Cataclysm to free everyone from the school but got turned into an image of the villain. Despite not having any powers Cat Noir managed to help Ladybug defeat Reflekta and return to normal with their full powers intact before heading back to the school.
In "The Puppeteer", after shaking off Adrien's bodyguard, Plagg and Adrien were taking a train to the movie theaters. But the movie and Plagg's attempt to try popcorn was put on hold when Alya turns into Lady Wifi, seeing that everyone is danger they transform into Cat Noir. The duo follows Lady Wifi to Marinette's house even though she was beaten, Lady Wifi didn't have the akuma but Puppeteer did. Heading to the news studio they find the young villain but Cat Noir ends up being controlled by her, despite being controlled Ladybug manages to capture the akuma returning Cat Noir and everyone else back to normal.
In "Antibug", after a series of attacks on Chloe; Plagg and Adrien transform and head to the Le Grand Paris to protect her. It turns out that she was attacked by an akumatizied villain named Vanisher who was actually Chloe's friend Sabrina using glitter they defeat her. Soon after that Chloe gets akumatizied into Antibug, buying time for Ladybug, Cat Noir fights Antibug but ends up in trouble (until an assist from Marinette) and gets free. With Ladybug back in action and a bag of marbles they were able to defeat Antibug and Plagg goes with Adrien to school the next day.
In "Volpina", Plagg was secretly watching Gabriel with Adrien who was curious about his father and gladly wanted to figure out his secrets. Phasing through the door into the safe Plagg went snooping around but nothing of interest opening the door for Adrien and they both take a book (which is the miraculous spellbook.) Upon reading it they see a picture Hawk Moth, but seeing Nathalie and the gorilla they head to school and come across a girl named Lila. But her series of lies and a harsh scalding from Ladybug leads her to getting akumatizied into Volpina. At one point Adrien tries to talk Lila out of causing trouble, Plagg was skeptical believing it wouldn't work and when it doesn't they transform into Cat Noir. On the Eiffel Tower the duo defeats and return home. But once they do Plagg was asked by Adrien if he moved his father's book and the kwami said no while eating Camembert.
In "Santa Claws", Plagg was celebrating Christmas with Adrien until they transform into Cat Noir. When the hero misuses Cataclysm, Plagg detransforms and falls on his back telling Adrien that he is cold and hungry. Heard Adrien apologize for his actions but wished him a "Merry Christmas" then with help from Santa Claus the two are brought back home. Afterwards they see that Ladybug's mistake led to Santa Claus being akumatized for real and they transformed again. Along with Ladybug they chased Santa Claws through the Paris streets using a box the duo manages to grab Santa Claws' hat, purify the akuma and save the holiday.
In "The Collector", after the events of "Volpina" Plagg explained that kwamis can't be photographed or filmed and took the pleasure of Adrien being banned from school. However, Adrien did not and they transformed into Cat Noir in an attempt to find Adrien's father's book. But that was put hold when Ladybug figured out Hawk Moth was Gabriel Agreste and when The Collector attacked the Agreste Mansion. Together with Ladybug they were able to stop him (unknown that Ladybug was right) and save Adrien's father.
In "Riposte", after Adrien's duel with the mysterious fencer; Plagg watched him do research on his opponent. Until it was interrupted by Riposte when she attacked and soon they were rushed to safety by Ladybug which didn't last long. As Ladybug and Riposte were fighting Adrien took the opportunity to hide but Plagg told him he was taking a lot of risks (transforming with a sprained ankle). However it was interrupted when Ladybug found them and made their way to Louvre Museum. While in the sarcophagus, Plagg wasn't to sure about disobeying Ladybug's orders but knowing she needed help they transformed into Cat Noir. Along with Ladybug after a fierce fight and using a radiator the duo was able to defeat Ripsote. Afterwards Cat Noir leaves to detransform and Plagg plops on Adrien's hand saying he was hungry until Adrien hid him and after Adrien makes up with Kagami the two head home.
In "Befana", Plagg went with Adrien to Marinette's birthday party but when Befana attacked the celebration they quickly hid. However, he was disappointed that he didn't get a chance to eat before transforming into Cat Noir. After getting Marinette to safety at the Eiffel Tower the hero leaves to deal with Befana and her angels. When Ladybug arrives the duo fights her all the way back to the tower. By using Cataclysm on a fire hydrant and a tuba the heroes were able to save Marinette's grandmother and returned to the party.
In "Robostus", Plagg went with Adrien to school hearing Max's concern about his friend Markov and seeing the robot's akumatization, the two quickly hid understanding that Markov did have emotions. But Plagg didn't care because Markov couldn't explore the pleasure of eating and transformed into Cat Noir. Meeting up with Ladybug the duo tried to reason with Robostus, but they get tossed out of the school and fight Robostus's army throughout the city leading to the stadium. During their fight Cat Noir and Ladybug get captured and almost have their miraculous taken by the villain who wants to make a wish to become human. But thanks to Max's intervention, a Cataclysm on Robostus's robot and a harp the heroes were able to stop the villain and head home.
In "The Dark Owl", over the past week Plagg had transformed Adrien into Cat Noir to save The Owl who is actually Mr. Damocles trying to be his own hero. After saving him for the fifth time Cat Noir and Ladybug talked on the rooftops on how to deal with him. Once Ladybug had an idea Cat Noir returned home for the night, after Adrien finished school the next day Plagg transformed him and went with Ladybug to Alya's house to ask a favor. Once they staged everything for The Owl, things took a disastrous turn which caused The Owl's identity to be revealed. By nightfall, Plagg was eating Camembert while watching tv but became shocked that their little plan caused Mr. Damocles' akumatization. After that they transformed into Cat Noir and headed to the stadium leading to a brief fight with the villain but resulted in the duo using their powers and tricked into a trap. To fool Dark Owl, Cat Noir and Ladybug detransformed and Plagg saw that Adrien's partner was Marinette surprising him but who was shushed by Tikki. While inside the crate Plagg shared a macaron with her to recharge and transformed again using Catclysm on the crate freeing them.
During another fight with Dark Owl they discovered that the akumatized object isn't on him but back at the school. Once there and setting off a chain reaction with a comic book Dark Owl was defeated, with The Owl becoming a hero smaller scale. Ladybug and Cat Noir had more free time after Ladybug leaves Cat Noir heads home.
In "Gigantitan", after Adrien's photo shoot was finished a young baby boy named August was akumatized into Gigantitan. When Adrien finds a hiding place, Plagg says he was about to a cheese break but transforms into Cat Noir then tried to lure the baby villain to the river but ends up getting caught. After a quick escape the heroes discovered that the akuma was in the baby's bracelet but didn't find it easy to get to with August being easily distracted. Once they were at the Eiffel Tower Cat Noir attempted to use Cataclysm on the kids bracelet however, the cat got thrown off and used it on an ice cone. Reuniting with Ladybug, with not much time left using a treat as a disguise and Cat Noir's bell the duo was able to finally capture the akuma and reunite August with his mother.
In "Glaciator", Plagg transformed Adrien into Cat Noir and worked with Ladybug to save people from a runaway bus and went home. Afterwards, once Plagg saw Adrien return to his room; and asked if he picked up a piece of cheese and was tossed a piece of Camembert. Seeing Adrien's eagerness about his date with Ladybug Plagg pointed out that he's in a hurry to get stood up by the heroine and was reminded that she didn't say yes either. But nonetheless Plagg and Adrien transform into Cat Noir complaining that he never gets to digest his food in peace. After being let down by Ladybug, Cat Noir came across Marinette who's having relationship problems too but soon became under fire by Glaciator once Marinette was safe the cat led the villain away. Along with Ladybug using a makeshift propeller and Cataclysm on a bus they were to save Paris from being buried under a mountain of ice cream.
Once the duo was alone so they could talk at the dating spot Cat Noir discovered Ladybug was in love with someone else and yet she considered the hero a close friend. Returning home, Plagg asked Adrien if he had a heart ache over Ladybug rejecting him and offered to share his cheese but after hearing Adrien talk about his romantic feelings about her. Plagg gets grossed out and desperately needed Camembert.
In "Sapotis", after witnessing the damage by the Sapotis on television after locking his cheese Plagg and Adrien transformed into Cat Noir. Meeting up with Ladybug, they discover that the Sapotis' clones disappear when their hats were destroyed but after going through many clones they had no luck and got completely overwhelmed. Once Ladybug understood the purpose of her Lucky Charm a teapot, Cat Noir did his best to hold off the Sapotis' but was overwhelmed again. Until the cat was saved by Ladybug and their new ally Rena Rogue using her mirage powers and Cataclysm on the villain's hats the trio were able to stop the little monsters.
In "Gorizilla", when Adrien's bodyguard was akumatized into Gorizilla and seeing Adrien plummeting to his doom Plagg advised him to transform. But Ladybug managed to save them but Gorizilla was still on the loose, having Adrien act as bait he heard Ladybug say that she needed Cat Noir and his Cataclysm for the plan to work. However, Plagg asked Adrien what rabbit is he going to pull out of his hat since he couldn't be in two places at once. With Wayhem acting as Adrien's double Plagg and Adrien transformed into Cat Noir using Cataclysm on the ground below the heroes were able to stop Gorizilla and returned home.
In "Captain Hardrock", seeing that Adrien was grounded from attending his friend's concert. Plagg tried to cheer him up by saying that he could enjoy the concerts from the comforts of home. As a friend Plagg tried to sing Adrien his own concert but with him still bummed the kwami flew away. When they witnessed Captain Hardrock's destruction he knew needed to be done and they transformed into Cat Noir. With Ladybug the duo tried to control the ship or anchor it with no success, but by using a chain on the ship's compass the vessel ran aground with everyone on solid ground Cat Noir used Cataclysm and destroyed the ship. After Gabriel agreed to let Adrien attend his friend's concert and Plagg enjoyed the music festival.
In "Frightningale", after Adrien was picked to be Cat Noir in Clara's video Plagg was very impressed with the costume. Commenting that he wasn't to fond of the bell but admitted the costume was something Adrien wanted deep down but the boy was more concerned that everyone would figure out his identity until Plagg assured him they wouldn't find out. Cancelling the shoot caused Clara Nightningale to be akumatized into Frightningale. Finding a hiding place Plagg and Adrien transformed into Cat Noir however even with Ladybug they found it difficult to fight her and became affected being forced to sing and dance. But thanks to a pair of handcuffs the heroes movements were synced preventing them from being turned into statues. Once using Cataclysm on Frightningale's mike and the Miraculous Ladybug returning everyone to normal and saved Clara's shoot.
In "Syren", after rounding up some escaped zoo animals while eating Camembert Plagg heard Adrien voice out his frustrations about Ladybug keeping secrets from him and was asked if he knew anything but Plagg said he couldn't be swayed. Until Adrien bribed him with cheese but he doved into Adrien's dirty socks to resist the temptation. As Adrien continued to bribe him Plagg hid inside the sock trying to drown him out and when he noticed the room was filling up with water he though he was safe but Adrien said this wasn't over and they transformed.
After finding Ladybug they knew they had to fight Syren underwater. Ladybug summoned her Lucky Charm and received a potion bowl and told Cat Noir had to wait while his partner sought out help. Fed up with waiting they detransformed, Plagg wondered what's taking her so long but became shocked when Adrien threatened to quit being Cat Noir if Plagg didn't tell him what Ladybug was hiding. However, when Plagg mentioned that he would care if Adrien quits and admitted that he was close friend. And they were approached by Master Wang quickly noticing the green vial Plagg understood what it meant saying he hated transforming.
Now with the playing field leveled both Ladybug and Cat Noir in their new "Aqua Mode" defeated Syren and saved Paris from flooding. Back at the mansion when Master Wang arrived Plagg introduced him to Adrien and when the master gave them a box of Camembert cheese with each wedge containing different powers Plagg complained that he hated transforming again.
In "Zombizou", once Ms. Bustier was akumatized into Zombizou but thanks to Ladybug's intervention Plagg escaped with Adrien and his classmates into the Locker Room. Seeing Adrien's act he asked him if it was a trick to get a kiss out of Ladybug but the boy said that he needed to work under the radar and transformed into Cat Noir. Understanding that Zombizou was after Chloe Ladybug, and Cat Noir decided to her to the Eiffel Tower but they lost their friends along the way. Soon even the cat got infected too and tried to kiss Ladybug but after Zombizou's defeat they went home. Plagg went to school with Adrien the next day.
In "Frozer", after saving a runaway para-glider Plagg and Adrien detransformed and went off to school. While inside Adrien's bag Plagg could tell that his wielder looked sad about Ladybug rejecting his offer, and when he saw Adrien give the rose to Kagami the kwami began to think he was crushing on someone new. When Adrien thought about changing his game Plagg gave him advice on how he greets Camembert although thankful his wielder told him that his advice might be best suited to someone else. During a visit at the ice rink Plagg was surprised that Adrien left Kagami for Marinette but Adrien told him she's just a friend. But soon the whole ice rink and all of Paris was getting covered in ice because of the akumatized villain Frozer. Thanks to the heroes new Ice Mode they were able to save Paris from being a frozen wasteland.
In "Style Queen", Plagg was eating Camembert while Adrien was getting ready for Fashion Week but felt awkward with the kwami commenting he looked ridiculous but heard someone coming and quickly hid. The show went well until Style Queen attacked turning Adrien into a golden statue, seeing what happened Plagg realized the predicament and flew off to Master Fu's place. While there he was eating Camembert until Marinette arrived meeting Tikki's owner, he talked to her about his owner's irresponsibility and offers to help her. But Master Fu was against it deeming the kwami of destruction too dangerous out without an owner, however Plagg asked when and the guardian reminded him of past incidents.
But when Ladybug had her back against the wall Plagg appeared and used Cataclysm on the Eiffel Tower, but had more destructive power. Seeing the damage he advised Ladybug to fix everything quickly with Adrien saved the heroine voiced concern about her partner but Plagg assured her he'd watch over him.
In "Troublemaker", Plagg was watching the show Fill My Shoes on television with Adrien. Curious Plagg asked Adrien why he was watching this show and Adrien explained he was supporting Marinette. During the show Plagg noticed the photos of Adrien in Marinette's room calling her another secret admire. But upon seeing the akumatized villain Troublemaker, before transforming Plagg asked Adrien to pick up a baguette for him. Meeting Ladybug at the bakery, the heroes had trouble catching Troublemarker due to her intangibility; playing a risk Cat Noir used Cataclysm and destroyed the villain's pen defeating her. Afterwards Plagg went to school with Adrien the next day.
In "Queen Wasp", after the show was over and Chloe transformed running off with the Bee Miraculous. Plagg and Adrien quickly transformed chasing after her with Ladybug but the job of retrieving the Miraculous was a lot harder as they found Chloe akumatized with it. By avoiding her wasps underwater and using Cataclysm to destroy the jewel the heroes returned Chloe to normal. Thanks to the Miraculous Ladybug (superpower) the Bee Miraculous was restored and returned to the duo.
In "Reverser", after noticing Ladybug being pulled around by Reverser while stuck in traffic, Plagg left with Adrien to transformed into Cat Noir. Upon joining Ladybug he saw that something wasn't right and being preoccupied the hero became an easy target causing him to be fearful of everything around him. Despite that Cat Noir was constantly supported and comforted by Ladybug, after finding and accepting help from Nathaniel and Alix. They went to the Eiffel Tower while tied to a kite Cat Noir blindly used Cataclysm on Reverser's hoverboard and saved Marc.
In "Anansi", after Adrien saw his friends in danger Plagg and Adrien transformed into Cat Noir. However with Anansi's great strength the heroes found it difficult to fight against her. Soon the cat was caught in Anansi's webs and when the villainess went for the ring Cat Noir invoked Cataclysm to protect it. With the help of their new ally Carapace the hero was set free, used his powers to destroy Anansi's helmet and saved Alya.
In "Sandboy", knowing that it was Nooroo's birthday Plagg told Adrien that he was going to sleep but made a lookalike of himself out of a sock and snuck out with a piece of Camembert, which was supposedly for the other kwamies. Meeting with Tikki he affectionately called her Sugarcube but Tikki brushed it and took the pleasure of her calling him Stinky Sock. Flying to Wang Fu's shop he along with Tikki expressed concern about getting in contact with Nooroo to the point where he cried but quickly hid it. Once they snuck past Wang Fu the pair flew into the Miracle Box, he and Tikki were greeted by the remaining kwamies, he told them the cheese he brought with him was used to feed a kitten (but ate it himself). Plagg and Tikki were thanked by Sass for coming and when Tikki tried to say her owner's name he reminded her of the magic spell that prevents them from doing so.
When Sass mentioned having the guardian's permission as well he and Tikki looked at each other nervously until Plagg led Tikki to the dance floor. When the time came to contact Nooroo, Plagg got into position and started singing after a while he and Tikki realized they wouldn't make it. He was sent by Sass to bring Wayzz in and with his help they were able to make a connection but with Hawk Moth instead of Nooroo. Knowing he was trying to track them Plagg and the others cut off the connection but realized that Hawk Moth akumatized someone so he, Wayzz and Tikki left to find their owners. They find the shop in chaos and Plagg was asked by Tikki if that was his owner hearing Nightmare Adrien's babbling he denied it. Realizing the damage, Plagg left to find Adrien on his way there the kwami was tailed by Sandboy but lost him by flying through the subway train and sees Adrien trapped in a cage but was relieved he was okay and yet wanted a good explanation but quickly transformed.
After facing their worst nightmares Sandboy was defeated. Back at Wang's shop Plagg quickly blamed the others but seeing how close Tikki was with her wielder he returned to Adrien to hug and thank him. Plagg was asked if something was wrong but the kwami thanked Adrien for letting him have his freedom mostly. And yet he completely understood why Plagg left saying he knew what it was like to have restricted freedom and all he had to do was ask. Touched he embraced Adrien again calling him the best Cat Noir ever but he doesn't want to get too mushy about it.
In "Catalyst", after dealing with a late night akumatized villain Plagg and Adrien return home and detransformed. The next day, while Plagg was eating Camembert he already knew they were heroes and wanted to go back to bed, however that's when Hawk Moth commenced his biggest plan yet. By amplifying his powers the mastermind sent a swarm of red akumas to the school, Plagg and Adrien attempted to transform but was halted by Gorizilla. With the okay from Adrien, he used Cataclysm on the street setting his wielder free and transformed into Cat Noir then joined up with the rest of his allies.
In "Mayura", despite the team putting up a good fight Cat Noir and Ladybug their lost allies as well as about to detransform back. But thanks to Cat Noir using Cataclysm on the ground below them the duo escaped, afterwards Plagg was given a piece of Camembert by Adrien but decided to share it and heard Ladybug express doubt on how to beat Hawk Moth. After hearing Adrien's words of encouragement they were found by the army Plagg and Adrien retransformed into their Aqua Mode. This time with the Paris rebellion's help the duo managed to corner Hawk Moth and deakumatize everyone. But their archenemy managed to escape thanks to Mayura despite that the team managed to save the city.
In "Chameleon", after Adrien was put to sleep by an akumatized Lila and shoved into a locker Plagg was unsure how to wake up him. While thinking he came up with the idea of using an enchanted kiss but was uncomfortable with it and yet realized no one would know. Just he was about to kiss him (thanks to Lila changing into someone else) Adrien woke up, when asked by him about what happened Plagg explained to Adrien that Lila put him to sleep with an enchanted kiss. Realizing that Lila was reakumatized Plagg and Adrien transformed to Cat Noir, despite being put to sleep by Chameleon again the cat saved Ladybug. Upon being woken up again the hero saw that Ladybug managed on her own and deakumatized Lila again.
In "Bakerix", after hearing from the news that Ladybug was fighting Bakerix, Plagg and transformed into Cat Noir. While confronting Bakerix the heroes try to tell him that they can be modern and still respect the past but the he doesn't listen trapping the duo. The hero opted to use Cataclysm to destroy the glass pyramid but was prevented by Ladybug and manage to escape through an escape shoot. They confront Bakerix again at the Startrain inauguration after using a ketchup bottle to make a non traditional sandwich and as a lure as well as using Cataclysm on a turbine cover. The heroes were able to obtain the flask and save Marinette's grandfather.
In "Backwarder", Plagg was heading to England by train with Adrien and his father to attend a wedding. But when Backwarder attacked he and Adrien left to transform into Cat Noir and met up with Ladybug. After getting struck by Backwarder's powers, using a pipe along with the heroine's most complicated plans ever. As well as Cat Noir using Cataclysm to destroy the brooch the duo was able to save Master Fu's friend Marianne. With that Plagg and Adrien returned to the train in time and came back home the next day.
In "Gamer 2.0", Plagg went to school with Adrien until everyone started disappearing. When Adrien said something smelt wrong, he suggested it might be Camembert but regardless the two transformed into Cat Noir. Meeting up with Ladybug, they were invited to play a game with Gamer but aware that it might be a trap the duo remained in contact. After playing a series of rounds with akumatized villain avatars the heroes managed to beat them all but for them to defeat Gamer they had to each others. Having no other choice but refusing to fight Ladybug, the kitty sacrificed himself by elimination and when Gamer was defeated the hero along with everyone was revived with the Miraculous Ladybug superpower.
In "Weredad", once August was brought back home after being deakumatized, Plagg was happy that Adrien finally had Marinette as a girlfriend knowing that her parents were the best bakers in Paris. Grabbing pieces of Camembert he didn't see the problem of liking two girls as it would increase Adrien's chances quietly commenting that both girls are one in the same. Joining Adrien in his bathroom, Plagg was reminded that he was in love with Ladybug. The next day, Plagg asked him when they would be leaving but was told to hide, in Adrien's room Plagg was reminded that they were only heading to the Dupain-Chengs to explain his true feelings then leaving. Seeing Adrien grab the rose from his food tray Plagg commented that giving it to Marinette would lessen her heartbreak and they transformed into Cat Noir.
However, breaking Marinette's heart led to her father Tom's akumatization into Weredad. After a sky high battle and working through a magical maze Cat Noir and Ladybug were able to bring both Tom and Marinette back safe and sound.
In "Silencer", Plagg was watching tv until he noticed an akumatized villain alerting Adrien with that they transformed into Cat Noir. But the hero came across a mute Ladybug after communicating with her through texting they come up with a plan. Back at the tv studio by having Ladybug make a fake Lucky Charm they tricked Silencer into activating the real one using a vacuum cleaner and Cataclysm to destroy Silencer's helmet. Everyone's voices restored Cat Noir and Ladybug saved Luka and got Bob to admit the truth about stealing everything from the Kitty Section band.
In "Oni-Chan", once school was over Plagg and Adrien went home with Lila on tow coming to "help Adrien" with his him. But when in Adrien's room he found it suspicious that Lila was snooping around and when she leaves. Plagg came out of hiding to ask Adrien why was he being so nice to Lila perfectly aware that she lies and was sneaking around his room unaware of what she was looking for. When Adrien points out that Plagg does the same thing he says he's only looking for cheese and counts his Camembert.
Then, sometime later he and Adrien were approached a once again akumatized Kagami, seeing her leave to punish Lila. Afterwards, Plagg knew that with so many admirers hovering around Adrien they'd end fighting over him nonetheless the two transform into Cat Noir. Figuring out that the horn on Lila's head acted as a beacon and having the villain switch places with a tied up Ladybug the heroes defeated Onichan saving Kagami and Lila.
In "Miraculer", after dealing with Destroyer things went from bad to worse when Sabrina was akumatized into Miracler. After the villain stole Cat Noir's powers and then being put on the receiving end of them, they detransformed weakened Plagg finally knew what being hit by his power felt like and decided to never to call dinosaurs names again. Once the duo rested a bit they retransformed despite being weakened and the whole team on deck they were able to stop Miraculer, were healed by the Miraculous Ladybug (superpower), keep the Bee Miraculous safe and have Chloe come to an understanding. Then Plagg went with Adrien to school the next day.
In "Oblivio", when Alya and Nino were akumatized into Oblivio during their field trip, Plagg and Adrien transformed into Cat Noir. However, their first fight with Oblivio resulted in Cat Noir using Cataclysm and being struck by the villain. In the elevator they detransform but upon doing so Plagg lost his memory and was picked by his wielder who mistook him for a genie. Plagg started sniffing Adrien's shirt but when the elevator started to collapse he refused to move until he knew what smelt so good in Adrien's shirt.
Phasing through the elevator door he called himself and the red one exceptional beings. After avoiding the villain and hiding in the bathroom, he said that the flying creatures were hungry and asked Adrien to open his jacket to see what smelt so good and saw that it was a wedge of Camembert cheese. Plagg grabbed it claimed that it was the most beautiful thing he ever saw and ate it. Once the group escaped to another part of the building Plagg tired of the situation refused to help despite being convinced by Tikki. He became offended when she called him selfish and a coward, saying he's more of a free spirit and leaves.
As he continued to fly out of the city, Plagg began to see advertisements of Adrien everywhere at first he called it psychological harassment and continued on his way. Still hurt by Tikki's words, Plagg continued to leave believing he's brave despite not remembering who he was. Seeing Oblivio's giant bubble and remembering Tikki's words, Plagg declared he wasn't a coward or selfish and went back wondering if Adrien had more cheese. Finding Adrien and his partner he asked if he could help and learned his name as well as the two retransforming into Cat Noir and soon with an amnesiac Ladybug's help the heroes were able to stop the villain and restore their memories.
Afterwards, when Adrien lamented about Ladybug finally for him and yet had forgotten about it Plagg agreed that it was a real bummer while eating a plate of Camembert.
In "Party Crasher", Plagg was reading a magazine while eating Camembert after Adrien's conversation with Wayhem. He suggest that Adrien take advantage of his father's absence by having a party but soon it was crashed by Party Crasher then he and Adrien transformed into Cat Noir. Despite the heroes putting up a fight he, Adrien and the team were captured by Party Crasher until they were freed by King Monkey. By making their movements unpredictable the team was able to stop Party Crasher.
In "The Puppeteer 2", Plagg was playing on the piano with Adrien but hid inside the instrument when Nathalie arrived reminding the boy of his trip to the wax museum. When he saw Marinette strangely leave the room she and Adrien were left alone in, by playing with the wax figure heads Plagg admitted that girls were complicated. But was told to put the figure head back before he breaks it after another part of Adrien's wax figurine was done the two leave the room. Finding Marinette, Plagg saw it strange that Adrien was freezing like a statue but was told it was going to work but it backfired. Soon things got worse when Manon was reakumatized into Puppeteer controlling the wax figurines in the museum then Plagg and Adrien transformed into Cat Noir. By switching the young villain's wand with a forgery the duo was able to save Manon.
In "Stormy Weather 2", when Adrien doubts that his life or his father will never change Plagg believes otherwise reminding Adrien of all the things that happened throughout the past months. Like how he went to school and made a bunch of new friends since then and yet Plagg couldn't figure out why someone enjoy going to school so much. And yet, when Adrien still had doubts about his father changing Plagg admits that's what he liked about people because you'll always know what's coming and reminded Adrien of all the times his father had changed. Even describing him as a type of cheese with a thick rind but with a soft inside or a slightly rotten inside. But their peaceful moment was ruined when they saw an erupting volcano outside Adrien's window. Plagg denied using his Cataclysm believing him the two transformed into Cat Noir.
Despite Stormy Weather's enhanced powers Cat Noir and Ladybug defeated her. Returning hearing Adrien continue talking on about the heroine, Plagg suggest that he take interest in another girl reminding Adrien of that Ladybug was interested in another guy. Hearing a knock at the door Plagg quickly hid and then upon seeing the similar writing from the note from Adrien's homework, that's when Adrien remembered the unsigned Valentine's letter. That's when they both thought it came from Marinette but easily brushed it off.
In "Timetagger", soon after they noticed that Mr. Ramier was akumatized again for the 24th time. Regardless the two transform into Cat Noir and made quick work of him but soon afterwards they had to deal with another villain from the future Timetagger. However they were short on time recharging in lavatory Plagg told Adrien to look on the bright side as he and Ladybug will remain in contact in the future and retransformed. Just as a villain came from the future so did some future help of their own, with the help of the future Miraculous holder Bunnix; Alix's future self and their future alter egos the group defeated Timetagger. But Plagg and Adrien had to transform again to defeat Mr. Pigeon again.
In "Ikari Gozen", when the building that hosted the friendship day game alarm warned them about an akumatized villain Plagg and Adrien transformed. Meeting with Ladybug; Cat Noir had discovered that the villain was Kagami's mother and held her daughter prisoner. After Ladybug retrieved the Dragon Miraculous and with Cat Noir's help they sent it by "special delivery" to Kagami and with her help as Ryoku the trio was able to save Kagami's mother.
In "Reflekdoll", Plagg advised Adrien not to take off his Miraculous for the photoshoot. However, Adrien ignored his warning, but was given the Miraculous for safe keeping. After Juleka is re-akumatized, Plagg was with Tikki, and seems to be unaware of the situation at first. Shortly after, they become aware and Plagg quickly tells Tikki to find their miraculous so they can be returned to their owners. Plagg finds the ring first and searches for Adrien. He quickly notices one of the Reflekta clones looking at him and assumes it's Adrien, only to discover it's Marinette. She ends up taking the ring and transforms herself into Lady Noir. Once Reflekta was defeated and Reflekdoll destroyed, Marinette gave the miraculous back to Plagg who returns to Adrien. Happy that Adrien will listen to his advice of never taking the ring off again.
In "Desperada", after Luka was safe Plagg and Adrien transformed into Cat Noir and went to meet Ladybug. Upon hearing the heroine's request for Adrien to wield the Snake Miraculous they detransformed and aware of the situation, Plagg thought this was a bad idea since Adrien couldn't be two heroes at the same time. But noticing that he wasn't listening Plagg was somewhat dissappointed that Adrien agreed. As Aspik, Plagg began to mock Ahim how about his teamwork with Ladybug seeing that Adrien was using his chances to charm the heroine instead of stopping the villain. When Plagg heard him, give up the Snake Miraculous he was happy that his owner cam to his senses but when Adrien was feeling down about Ladybug not having fond memories of him. Plagg encouraged him to make up for it as Cat Noir and they retransformed with the help of their ally Viperion the trio was able to stop Desperada and save everyone.
In "Ladybug", after hearing that Marinette got expelled from school thanks to Lila. But Plagg became annoyed that they had to help Ladybug in fighting Mayura (unaware it's a trap) and yet was assured that after they help Ladybug they'll help Marinette too so they transformed into Cat Noir. The hero continued to fall for the villainess' trap until the "real Ladybug" revealing the deception and that the imposter Ladybug was a sentimonster, during a brief fight they managed to a hold of the creature. But instead of destroying the sentimonster she was given her freedom and Cat Noir like the idea of working with two Ladybugs and yet it was short lived when Mayura destroyed her.
Cat Noir was consumed with angered and went to attack Mayura but was stopped by Hawk Moth and after another fight led to a stalemate. When Hawk Moth tried to take Cat Noir's ring the cat used his Cataclysm to protect it but was thrown off the building by the mastermind but was saved by Ladybug knowing that they could get their enemies Miraculouses another day.
In "Startrain", after a late night fight; Plagg and Adrien returned home. Aware of their school field to see Big Ben in London Plagg wanted to enjoy a vacation away from the akumas. However, their peaceful field trip was ruined when an akuma unknowingly snuck aboard the Startrain and akumatized Max's mother into the titular villain so they transformed into Cat Noir. With having to capture the akuma and teleport everyone back to earth at the same time the duo called upon their newest allies Pegasus using his powers of teleportation and Markov. The group battled their way through the train and made their way back to earth.
In "Feast", when Plagg saw that Adrien was looking sad while playing the piano he asked him what's wrong and Adrien said that Nathalie's condition reminded him of his mother. Knowing of a way to cheer him up Plagg offered to perform a duet which left Adrien surprised that he knew how to play, after playing he was thanked for by Adrien it being told that his mother made him laugh the same way. During the night Plagg was sleeping beside Adrien with a piece of camembert until he became shocked that Wayzz was trying to removed the ring returning to his Miraculous and placed back in the Miracle Box. But thanks to Adrien showing her bravery in the face of danger Plagg was reunited with his owner and they transformed into Cat Noir. When the heroes dove into the belly of the beast they were able to destroy the sentmonster by using Cataclysm to destroy the staff and restore the Order of the Guardians.
In "Kwamibuster", during their wielder's class, Plagg was going below to eat what he called the "magic cheese" in the Science Room and was warned by Tikki that he should've found it strange that this cheese kept appearing out of nowhere but started eating. Upon seeing Ms. Mendeleiev's attempt to capture them, he was grabbed by Tikki and tried to flee being reminded that's the reason why he should've listen to her but refused to leave without finishing his cheese first afterwards he returned to Adrien. Soon Plagg met up with Tikki to discuss what happened earlier telling him of her concerns but reminded her of their abilities was assured nothing would go wrong.
However he received a scalding from Adrien at school the next day saying on how irresponsible he was and retorted to saying that Adrien was as much fun as Sugarcube speaking of Ladybug's kwami Tikki. Upon hearing Adrien figure out that Tikki was there too, Plagg started to worry that he may have revealed the heroine's identity. He gave his wielder the advice of acting that nothing was wrong but upon being asked if Marinette was Ladybug, Plagg denied it aware that if Adrien's identity gets out he can't be Cat Noir anymore. Seeing that their little adventure caused Ms. Mendeleiev's akumatization the two transforming into Cat Noir but after being struck by Kwamibuster, Plagg was separated from Adrien. Then, tried to get out of Kwamibuster's canister but told by Tikki to save his energy and when he opted to Cataclysm she told him it was a bad idea as he couldn't control it. Then asked if Tikki had a plan and yet retorted she didn't but trusted that her owner did have a plan.
Seeing more of his kwami brothers and sisters being captured Plagg at first believed they were doomed but was happy seeing her wielder appear as (Multimouse) then fused his powers with Mullo becoming "Multinoir". After using Cataclysm to set the other kwamis free, Kwamibuster was defeated, Plagg returned to Adrien and told him to convince Ladybug that he goes to a different school and retransformed taking Ms. Mendeleiev back to the school.
In "Cat Blanc", after Ladybug was spotted leaving Adrien's room but left a gift on his bed. Plagg quickly guessed that Marinette asked the heroine to deliver it for her but when Adrien figured out that the heroine and Marinette were both one and the same. He quickly tried to dissuade him knowing of the consequences if either of their identities were revealed but was assured by Adrien that everything would be fine and yet still wasn't convinced. After his wielder and Marinette became a couple everything seemed perfect until Gabriel threatened to break them up, upon seeing an akuma heading straight for Marinette the two quickly transform into Cat Noir and used Cataclysm to destroy it. Despite everything going well it unraveled when the duo discovered Hawk Moth's identity and purpose as well as too make matters worse they were akumatized into Cat Blanc and by forcing to choose the akumatized hero destroyed everything and everyone.
Ever since then Plagg and Adrien remained in their akumatized form until Ladybug from the past came to help deakumatize them. When she returned to the past to fix her mistake the future of them being akumatized was erased. Eyeing the gift, Plagg liked the idea of cheese being a lot better than a beret.
In "Felix",upon hearing Gabriel's angry response towards the thought of Emilie being replaced Plagg described him as Tome cheese. But was calmed down by Adrien being reminded that it was the anniversary of Emilie going missing. However, things were stirring when Adrien's cousin Felix came to visit, and seeing how sneaky he was; Plagg told his wielder what Felix was doing. Despite that, Plagg was told not to be so hard on him due to the fact that Felix lost his father, still angry he snappily compared the two of them but upon seeing his wielder's sad expression the kwami apologized. Things were even more complicated when Felix's deception caused some of Adrien's friends to be akumatized into the Punisher Trio. Thinking it's what Felix's deserves Plagg questioned why do they have to save him was answered it was the right thing to do and they transform into Cat Noir. Thanks to a can of whipped cream setting off an chain reaction between the villainous trio the heroes were able to save Felix. Back at home, Plagg was given an apology by Adrien that if he was more observant of his cousin then all the trouble wouldn't have happened. Then was given new cheese and Plagg forgave Felix saying he could come back anytime.
In "Heart Hunter (The Battle of the Miraculous - Part 1)", when he sees Adrien admiring a picture of Kagami and Marinette, Plagg compliments him for starting to realize just like cheese there are many types of girls in this world. Upon seeing that Heart Hunter was on the loose the two transformed into Cat Noir, even with Ryuko's help they found it strange that the villain was deakumatized afterwards they detransformed and met up with Kagami.
In "Miracle Queen (The Battle of the Miraculous - Part 2)", upon seeing a swarm of hornets coming after them, to escape Plagg activated his Aqua powers and they retransformed into Aqua Noir. Reuniting with Ladybug, the duo discovered that Chloe was akumatized again into Miracle Queen but to make matters worse, all their allies and Master Fu were captured and Hawk Moth was in possession of the Miracle Box. Through the powers of fusion as Snake Noir and Dragon Bug, they were able to save their allies, stop Hawk Moth, Mayura and reclaim the Miracle Box.