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Mega Leech

Season 4, episode 10 (Production order); Episode 88 (Overall)

Read transcript
Do you realize how many fears you've managed to overcome? The objects that help you get over your fears are just like the Miraculous and you fight everyday to defend a cause without anyone noticing. That's just like having a secret identity. And this, you already are a superheroine. You just need one last badge. Mylène Haprèle, I am proud to entrust you with the Miraculous of the Mouse. You will use it for the greater good.

Ladybug, "Mega Leech"

"Mega Leech" is a Season 4 episode of the series, Miraculous: Tales of Ladybug & Cat Noir. As based on the series' production order specifically, "Mega Leech" is the 10th written and produced episode of Season 4. It is also the 88th written and produced episode of the series, overall.


When Marinette and her friends go to protest against the deforestation of a square in Paris, Mayor André Bourgeois is enraged and is akumatized. Now Ladybug will have to defend not only the square, but all of Paris!


The episode starts with Mylène who is afraid of protesting against the mayor, but Ivan tells her not to be afraid and supports her. Meanwhile Marinette who is in her bedroom, is woken up by the noises in the nearby park as Mayor Bourgeois announces that he is keeping his word about keeping Paris clean continuing on from "Reverser" by unveiling plans for Project Oxygen. He starts by saying that he is building a tower that can reduce pollution and produce filtered oxygen for Parisians. The construction of the building would replace the park of Place des Vosges, which prompts Ivan and Mylène to arrive at the Place des Vosges to protest against it. The mayor gets disturbed by Ivan and Mylène and order Roger to keep them away as they are protesting against him. Mylène and Ivan refuse to back down, and end up being escorted home by Officer Roger. Marinette witnesses this and asks Tikki if she should transform to help them out. Tikki replies that the police normally take care of bad guys and is then cut off by Tom calling for Marinette.

Marinette then notices she is getting late for school and immediately arrives in Collège Françoise Dupont. When she arrives in Miss Bustier's class, Miss Bustier questions her about Mylène and Ivan's whereabouts and is informed that they were protesting against the Mayor in the park and taken home by Roger. Alya explains that Mylène and Ivan were trying to stop the Mayor's plan to destroy the park and replace it with artificial oxygen and a tower. Miss Bustier tells the class she thinks Officer Roger made a big mistake, then calls him. Picking up the call, Roger asks if there's a problem with Sabrina, and Miss Bustier says she has a problem with Ivan and Mylène being escorted by police home for protesting against the destruction of the park. She requests that the two be driven back to the park and angrily hangs up to bring the whole class to the building site. Along with Miss Bustier the whole class arrives at the Place des Vosges and protest against the mayor together by blocking the trees. Mayor Bourgeois then tries to convince everyone it would result in less pollution on which Mylène replies the trees are a natural source of oxygen, and they shouldn't be replaced by artificial means. Mayor Bourgeois then shows the commercial for their oxygen project which features the Gabriel and Tsurugi brand.

Ivan comforting Mylène for the protest against Mayor

After watching the commercial, everyone falls for it except Adrien. He is confused because he was told by his father it was just a advertisement for Gabriel's next perfume. Mylène tells everyone that the Mayor of Paris is showing these advertisements just to manipulate them, and just wants to make money out of it. Marinette, then just to show everyone the mayor is actually wrong about the benefits of his project, explains to the mayor that Mylène and Ivan may have misunderstood and says that trees and fresh air is free, but the Mayor wants to replace the natural park with artificial oxygen taken from polluted air so it could be cleaned and sold in plastic bottles that will end up in landfills. André replies that Marinette is right and panics when the crowd becomes astonished by his idea. Alya then spreads the message via her Ladyblog and tells her viewers that the park is being closed. Miss Bustier then says that if Mylène and Ivan want to stop it then she is with them. André attempts to get Roger to stop the students but Roger admits that he actually agrees with them. Various civilians show up to join the protests and everyone gathers together to protect the trees. Mayor Bourgeois is overwhelmed by reporters and is badgered by Nadja Chamack about the project. Shadow Moth senses the anger and frustration of the Mayor, then akumatizes him into Malediktator once again with a sentimonster to assist via amokization, Mega Leech who can shrink and multiply.

Malekdiktator then jump into his sentimonster's stomach, Mega Leech, and commands it to make millions of clones of himself. Everyone attempts to flee but Mega Leech's Malediktator clones spread out and enter the eardrums of various civilians. Ivan takes a hit for Mylène and she fearfully escapes. Adrien hides behind a pillar nearby to transform.

Marinette attempts to transform in an alley but is stopped by Mylène who suggests that they hide in the sewers. Marinette then makes an excuse that she can't hide in sewers because she is afraid of them. Mylène reveals that she is afraid of the dark, humidity, germs and even mice and was also scared of protesting against the mayor but she overcame them and found the courage to move on and accepts that it is a natural reflex. Mylène then gives her a badge that she always carries with her all the time in case she gets scared. Marinette accepts the badge and goes inside the sewers. Marinette acts like a mind controlled victim of Malediktator and scares Mylène off. Tikki appears and Marinette admits that she didn't have a choice then quickly transforms.

Ladybug meets up with Cat Noir and immediately summons her Lucky Charm and gets an ice skate. The ice skate is then used to destroy the nearest clone's sash, releasing an akuma and amok. Ladybug was just about to use her Miraculous Ladybug but she is stopped by Cat Noir, who points out that Mega Leech and the Malediktator clones are still causing havoc. Ladybug then realizes when Malekdiktator used his sentimonster to clone himself, the Amok and Akuma might have multiplied too. Ladybug asks Cat Noir to distract the clones so she can buy some time. Cat Noir questions why he is always the one distracting others, but Ladybug leaves without saying anything.

In the Sewers, Mylène is crying and blaming herself for this problematic situation. Ladybug consoles Mylène and reveals that she knows how to defeat Malediktator. As she begins to give Mylène a Miraculous, Mylène stops her by admitting that she has so many fears and she isn't worthy because of them. Ladybug then tells her that she has overcome many of those fears and all the badges she ever used are like the Miraculous and she fights every day to protect a cause without being noticed like having a secret identity. Additionally, Ladybug tells her that Mylène is already a superheroine and she just needs the last charm. Mylène finally accepts the Mouse Miraculous and immediately Mullo frightens her, causing Mylène to cower behind Ladybug. Ladybug tells Mullo that is not cool and tells Mylène that "true bravery is not the absence of fear, it is to continue even with fear". Mylène finally transforms into Polymouse. Polymouse then inquires about the plan to which Ladybug replies that she is going to take care of the sentimonster and Polymouse will take care of the clones. As she came around the sewers end, she overcomes her fear and activates Multitude, her power. Polymouse uses her power to multiply herself and the ice skate which Ladybug got via her lucky charm. She then frees all of the people under the clones' control while Ladybug meets back up with Cat Noir, unaware that he also fell prey to Malediktator's control. Polymouse quickly gets rid of the clone.

After all the civilians are freed from Malekdiktator's control Ladybug gathers the rest of the team, but excludes Rena Rouge, Viperion and King Monkey. Cat Noir, after seeing the team gathered he asks for them to wait for him to make a group pose. Ladybug then tells Pegasus to teleport Vesperia over the sentimonster so she can paralyze it. Vesperia leaps through the Voyage and appears above Mega Leech and stuns it with Venom. Meanwhile Polymouse defeats the last of the clones. Ladybug commands Ryuko to gather the akumas and amoks into a swarm to contain them. Ryuko uses the wind dragon to create the swarm. Ladybug then gestures for Carapace to use Shell-ter and together they defeat the sentimonster. Polymouse after defeating the clones, ends her Multitude and gives back the ice skate. Ladybug uses her Miraculous Ladybug to revert everything back and repair the damage caused by the supervillain. Ladybug creates a Magical Charm for André. Before leaving, Ladybug advises André to do what is right for Parisians and leave the Place des Vosges alone. All the temporary heroes give back their Miraculouses to Ladybug. Back in the sewers again, Ladybug arrives with Polymouse to take back the miraculous from Mylène. Before leaving, she tells her she was super brave today, and she should be super proud.

Shadow Moth in his lair gives his usual revenge spiel. The mayor announces that after listening to the young Parisians, he is cancelling Project Oxygen. After all they are the future, and in future trees would continue to filter the fresh air. The Mayor announces that he is to plant a tree in the park. Marinette congratulates Ivan and Mylène on winning their protest. The Mayor struggles to plant the tree and the students offer to help. In the Agreste mansion, Adrien arrives back and is asked by Gabriel why he stood up against him at the protest. Adrien argues that he was just against the project his friends proved was bad for Paris and for the planet. Gabriel interrupts and orders him to go to his room. Adrien sadly obeys. Gabriel turns around and twists Emilie's ring on his finger before the end card appears.


Major Characters

Minor Characters


  • Internationally, this episode first premiered in Brazil on Gloob.
  • Despite Shadow Moth knowing the identities of Nino and Max, as well as Kagami, Ladybug still entrusts them with the Turtle, Horse, and Dragon Miraculous respectively as she needed their help to contain Mega Leech and the akumas and amoks it replicated.
  • This is the sixth episode where an akuma swarm appears, after "Ladybug & Cat Noir", "Stoneheart", "Catalyst", "Mayura" and "Ladybug".
    • This is the first episode where amoks are also in the swarm.
  • The thumbnail of the official trailer features Malediktator, making it the fourth one to have some other character other than the titular one on it, following "Ikari Gozen", "Félix", and "Ladybug".
  • This is the third time André Bourgeois gets akumatized into Malediktator, following "Malediktator" and "Mayura" and including his akumatization in Heart Hunter, it's his fourth overall akumatization.
  • This is the fourth episode to be named after a sentimonster, the others being "Reflekdoll", "Ladybug" and "Gabriel Agreste".
  • Mylène Haprèle receives the Mouse Miraculous in this episode to become the superheroine "Polymouse".
    • However, despite becoming a superhero in this episode, her superhero name is not mentioned, making her the seventh showed Miraculous holder not to have their superhero name stated in the show, following Master Fu as both the holder of the Peacock and Turtle Miraculouses, Multimouse's unifications with the Ladybug and Cat Miraculouses, Cat Noir's unification with the Cat and Snake Miraculouses, and Ladybug's unification with the Ladybug and Bee Miraculouses. Though, Mylène's superhero name is mentioned in the later episode "Penalteam".
  • This is one of the few episodes where Marinette isn't in the very first scene.
  • It's revealed that Ivan sometimes calls Mylène "little mouse", which is a coincidence as Ladybug later gave her the Mouse Miraculous.
    • It is also revealed that Mylène calls Ivan "Teddy Bear".
  • Mayor Bourgeois mentions a space dumpster program, as seen in "Reverser".
  • According to the project's commercial, Project Oxygen was a collaboration between the City Hall, Gabriel, and the Tsurugi brand.
  • This is the fourth time in Season 4 where Cat Noir transforms on-screen, following "Lies", "Psycomedian", and "Gabriel Agreste".
    • This is one of the few episodes where Cat Noir transforms on-screen and Ladybug doesn't.
      • Coincidentally, this also happens in the previous episode, "Gabriel Agreste".
  • This episode makes it the second highest superpower count at eight individuals (Shadow Moth having two Miraculous simultaneously), with "Miracle Queen" being the highest at nine individuals, although eleven powers were used in Miracle Queen as opposed to the nine in this episode.
  • It's revealed that Mylène's badges, pins, and pendant serve to help her overcome her many fears. She also is shown to do a special ritual before any big event (like a protest) to give herself courage to face her fears.
    • Her fears include the dark, humidity, germs, protesting, and ironically, mice.
    • Her Ladybug badge reminds her of her fear of water, while her panda badge reminds her of her fear of bees, and her pendant helps her get over her fear of badges.
  • It is revealed that Mylène and Ivan have been doing a protest against Project Oxygen for six months.
  • This is the third time when the Miraculous Ladybug superpower is stopped following "Reflekdoll" and "Oblivio".
  • Unlike in "Sapotis", where the original villains only had the akuma while the clones didn't the opposite happened where all the Malediktator clones had both akumas and amoks.
  • Like "Malediktator", Cat Noir ended up mind controlled and didn't fight Ladybug but only held her captive just to take her Miraculous.
  • This is the third time an akumatized object is destroyed by someone other than Ladybug and Cat Noir, following Fang in "Lies" and Marianne Lenoir in "Furious Fu".
    • This is the first time an akumatized object was destroyed by a superhero other than Ladybug and Cat Noir.
  • This is the second time a kwami scares its owner upon meeting them, after Marinette in "Ladybug & Cat Noir".
    • Unlike how it happened between Marinette and Tikki, where the latter scared the former unintentionally, Mullo scared Mylène on purpose.
  • This is the second time where a holder rejects wanting a Miraculous before it is given to them, following Zoé Lee in "Queen Banana".
  • This is the fourth time where someone else other than Ladybug uses her Lucky Charm following "Queen Wasp", "Reverser" and "Reflekdoll".
  • This is the 7th time in the series that someone kisses someone on the lips. Following "Oblivio", "Cat Blanc", "Dark Cupid", "Zombizou", "Chameleon", and "Horrificator".
  • More insight about the Mouse Miraculous is revealed:
    • The holder of the Mouse Miraculous can summon the power of Multitude without using the skip rope.
    • On an interesting note when Marinette used Multitude in "Kwamibuster", despite her wearing the remaining Miraculouses copies of the jewels didn't appear on the other clones but when Polymouse used the power the Lucky Charm object duplicated with her it's unknown why.
    • Meaning that the power is capable of multiplying objects (outside of the Miraculouses) as long as the user is holding or wearing them.
    • It's also unknown if there is a way to tell a difference between the original and the clones.
  • Like several other episodes, Cataclysm isn't used.
  • The way Marinette pushed Alya is similar to what she did with Kagami in "Mr. Pigeon 72".
  • This is the sixth time where Ladybug's Lucky Charm resembles an akumatized villain's object both before it got akumatized following "Pixelator", "Reflekta", "Frightningale" "Sandboy", and "Miraculer".
  • This is one of the few episodes with obvious sociopolitical themes. It deals with corrupt businessmen destroying the environment, government collusion with corporations, cover-ups and downplaying of controversies by politicians, activism, and the disruption of protests by police.
    • In a way, the theme of this episode is similar to the Dr. Seuss story "The Lorax" and its 2012 film adaptation. Both feature young characters going against adults who cut down trees and sell oxygen.
    • Interestingly, the show was originally meant to be written for teens and would've featured more political themes.
  • This is the third time someone ends up inside a sentimonster following "Reflekdoll" and "Feast".
  • This episode is the second episode animated by SAMG Animation this season, which will be the last season SAMG will be working on.
  • Mylène has the same reaction as Marinette in "Ladybug & Cat Noir", in which both characters first become miraculous holders but can't handle the challenge because of their fears, but in the end, they manage to face their fears head on.


  • When the akuma and amok fly out of Hawk Moth's lair, the Eiffel Tower is in the background.
  • When Ladybug is getting the Mouse Miraculous from her yoyo, the light does not flash the pink with black dots pattern. Instead it is just a normal white light.
  • When Mylène gets the Mouse Miraculous it enters in Mylène's camouflage mode, but in the next scene the Mouse Miraculous is shown in its activated mode.
  • During Mylène's transformation, both the hair she usually has and the hair she has as Polymouse are present when Mylène gets her mask.
  • Polymouse jumps into Cat Noir's cat ears, which are obviously just flaps of fabric clipped to his hair. However, she could somehow enter his brain, and there's even a view of his regular ear canal.
  • When Ladybug entrusts the Dragon Miraculous to Kagami, the beaded accessory is longer than normal resembling a necklace and not a choker.
  • Although Ladybug used the Miraculous Ladybug and her suit has returned to normal, when she arrives at André to give him the magical charm she returns to the previous suit, but when the camera changes angle she returns to normal, and then, it changes again and she returns to the other suit one more time.
  • When Vesperia jumps down, her braid clips out of her body.
  • When Vesperia uses Venom on the sentimonster, she doesn't have an elbow.
  • When Ladybug entrusts the Horse Miraculous to Max, the glasses have a different design.
  • In one scene, Ladybug appears to have an extra left pigtail.
  • When Ladybug purifies that first akuma and amok, she says "Bye bye!" without opening her mouth.
  • When Ladybug prepares to swing away after giving André the charm, her yo-yo phases through Vesperia's head.
  • In the Italian Dub, the whole ad of Project Oxygen is silent, except for Adrien’s part.


Click here to view the image gallery for Mega Leech.
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ve Episodes
Season 1
101 Stormy Weather102 The Evillustrator103 Lady Wifi104 Princess Fragrance105 Dark Cupid106 Mr. Pigeon107 Pixelator108 Copycat109 The Bubbler110 Simon Says111 Rogercop112 Gamer113 Animan114 Darkblade115 Pharaoh116 Timebreaker117 Horrificator118 The Puppeteer119 The Mime120 Guitar Villain121 Reflekta122 Ladybug & Cat Noir (Origins - Part 1)123 Stoneheart (Origins - Part 2)124 Antibug125 Kung Food126 Volpina
Season 2
201 The Collector202 Prime Queen203 Glaciator204 Despair Bear205 Troublemaker206 Gigantitan207 Riposte208 Befana209 Frightningale210 Gorizilla211 Robostus212 Sapotis213 The Dark Owl214 Syren215 Zombizou216 Captain Hardrock217 Frozer218 Style Queen (Queen's Battle - Part 1)219 Queen Wasp (Queen's Battle - Part 2)220 Reverser221 Anansi222 Malediktator223 Sandboy224 Catalyst (Heroes' Day - Part 1)225 Mayura (Heroes' Day - Part 2)226 Santa Claws
Season 3
301 Chameleon302 Animaestro303 Bakerix304 Backwarder305 Reflekdoll306 Weredad307 Silencer308 Oni-Chan309 Miraculer310 Oblivio311 Desperada312 Christmaster313 Startrain314 Kwamibuster315 Feast316 Gamer 2.0317 Stormy Weather 2318 Ikari Gozen319 Timetagger320 Party Crasher321 The Puppeteer 2322 Cat Blanc323 Félix324 Ladybug325 Heart Hunter (The Battle of the Miraculous - Part 1)326 Miracle Queen (The Battle of the Miraculous - Part 2)
Season 4
401 Truth402 Lies403 Gang of Secrets404 Mr. Pigeon 72405 Psycomedian406 Furious Fu407 Sole Crusher408 Queen Banana409 Gabriel Agreste410 Mega Leech411 Guiltrip412 Crocoduel413 Optigami414 Sentibubbler415 Glaciator 2416 Hack-San417 Rocketear418 Wishmaker419 Simpleman420 Qilin421 Dearest Family422 Ephemeral423 Kuro Neko424 Penalteam425 Risk (Shadow Moth's Final Attack - Part 1)426 Strikeback (Shadow Moth's Final Attack - Part 2)
Season 5
501 Evolution502 Multiplication
Future episodes
503 Destruction504 Jubilation505 Illusion506 Determination507 Passion508 Reunion509 Exaltation510 Transmission (The Kwami's Choice - Part 1)511 Deflagration (The Kwami's Choice - Part 2)512 Perfection513 Migration514 Derision515 Intuition516 Protection517 Adoration518 Emotion519 Pretension520 Revelation521 Confrontation522 Collusion523 Revolution524 Representation525 Conformation (The Last Day - Part 1)526 Re-creation (The Last Day - Part 2)527 Action
Season 6
Season 7
Season 8
2 Part Episodes
The Origins StoryQueen's BattleHeroes' DayThe Battle of the MiraculousShadow Moth's Final Attack
Christmas specials
Santa ClawsChristmaster
Football special
Future episodes
The Kwamis' ChoiceThe Last DayMiraculous: One Night MissionMiraculous & Ghostforce crossover
Miraculous World
Miraculous ShanghaiMiraculous New YorkMiraculous LondonMiraculous DakarMiraculous RioMiraculous Tokyo
Unknown/Cancelled specials
Ladybug in Halloween
Future movies
Ladybug & Cat Noir: The MovieUntitled second theatrical film
Cancelled/Unknown movies
Miraculous (live-action film)Miraculous Lady Bug
Miraculous Secrets
Marinette in ParisMarinette and FashionLadybug as seen by AdrienLadyblogAdrien's Double LifeMarinette and AlyaMarinette's Double LifeCat Noir as seen by MarinetteMy Birthday PartyMarinette and AdrienMaster FuTikkiPlaggFriendsNinoMaxMylèneRoseAlixSabrinaIvanGabrielNathaniel & MarcMarinette as seen by ChloéLilaHawk Moth and the Akumatized VillainsFamilyKagami as seen by MarinetteKagami as seen by AdrienLuka as seen by MarinetteNew PowersNew HeroesMayura and the SentimonstersChloé as seen by MarinetteNathalie as seen by GabrielFeelings
Tales from Paris
The NotebookInspirationRepetitionBusy DayHomework Essay
Miraculous Zag Chibi
Rooftop DinnerCatnip FragranceThe ChaseCuriosity Kicked the CatCutest Cat FightFatal PosyScarybug
Future webisode
Other media
Released media
The Mini Menace LadybugLadybug PVFirst CGI promotional videosHappy Birthday to You!Ladybug (musical)Miraculous Ladybug (musical)Miraculous: The Ladybug ShowMiraculous Ladybug COVID-19 SpecialLadybug Saves Christmas
Future media
Miraculous Ladybug COVID-19 Special 2Action
Cancelled/Unknown media
Miraculous Ladybug OVAMiraculous (live-action TV series)Miraculous LiveGagotor