History TookALevelInJerkass / WesternAnimation

** In Season 1, [[Characters/TheAmazingWorldOfGumballGumballWatterson Gumball Watterson]] was almost as much as a CheerfulChild as Darwin. After the first, and especially during the second, he was more acerbic and more of a DeadpanSnarker. Even in the first season, however, he could be rude at times, so it seems it's more of a shift in attitude.

** Raspberry Tart/Torte in the 2021 incarnation, with the addition of being upgraded to an AlphaBitch.

* Eddy from ''WesternAnimation/EdEddNEddy'' went from an UnluckyEverydude to a JerkWithAHeartOfGold to a greedy bastard due to {{Flanderization}}. Reversed in TheMovie, where we find out that Eddy was just acting that way because [[spoiler:he idolized his older brother, who we find out is a far bigger bastard]].

* ''WesternAnimation/EdEddNEddy''
** Eddy went from an UnluckyEverydude to a JerkWithAHeartOfGold to a greedy bastard due to {{Flanderization}}. Reversed in TheMovie, where we find out that Eddy was just acting that way because [[spoiler:he idolized his older brother, who we find out is a far bigger bastard]].
** Kevin did this too, going from simply disliking the Eds to sometimes going after them without provocation. "Your Ed Here" and "Smile For The Ed"[[note]]Where he spreads Eddy's unflattering school picture everywhere[[/note]] were the pinnacles of this.

** Bloo is shown as the perfect ImaginaryFriend in the pilot/TV movie, but just one episode later he has become a self-absorbed jerk who [[WithFriendsLikeThese verbally and/or physically abuses Mac]] OncePerEpisode. [[WMG/FostersHomeForImaginaryFriends It's possible]] that living in an OrphanageOfLove might ironically have something to do with it: He wasn't used to having so much freedom before moving into Foster's, so it apparently inflated his ego.

** Princess Bubblegum was given a few morally ambiguous traits in some of the earlier episodes. She sometimes let her anger get the better of her and would mercilessly pursue those who had wronged her. Some of her science experiments also went wrong, such as producing her extremely screwed up offspring Lemongrab. However, more often than not Bubblegum would show regret when she screwed things up, and work to fix her mistakes. Over the course of season 5, her actions turn from well meaning mistakes into outright atrocities, such as committing genocide on a group of defective robots, sacrificing one of her subjects because she thought he wasn't as valuable as Finn or Jake, throwing Tree Trunks' entire wedding into prison just because Tree Trunks preferred the fake King of Ooo preside over her wedding than her, causing almost the entire conflict of one episode just because she doesn't like people thinking of magic as anything than another kind of science, and in general showing no remorse for hurting people if she believes it's for the greater good. A canon video game also reveals that she trapped and performed painful experiments on the two Lemongrab brothers, when she had previously been shown trying to help them. The only reason she doesn't come across as a villain is because of the nature of these threats, namely evil!Lemongrab and that the fake king intended to make everyone his servants. She does [[TookALevelInKindness mellow out]] after Flame Princess gives a [[WhatTheHellHero serious]] [[TheReasonYouSuckSpeech piece]] of her mind.

** In Season 1, Gumball was almost as much as a CheerfulChild as Darwin. After the first, and especially during the second, he was more acerbic and more of a DeadpanSnarker. Even in the first season, however, he could be rude at times, so it seems it's more of a shift in attitude.

** Roger was a pretty plausible Jerkass to begin with, though (DependingOnTheWriter at least) could occasionally show compassion and restraint in his antics. In later episodes the callousness of his actions and schemes border outright FauxAffablyEvil territory. For example, in "Virtual In-stanity", he [[DisproportionateRetribution/AmericanDad hunted down five frat boys who stiffed him $20]], then killed some more random people just because he's "got the blood lust".
** In contrast, Stan's own Jerkass tendencies have become more toned down in favor of turning him into a borderline Peter Griffin clone, or at least more [[WellIntentionedExtremist well-intentioned]] as the show has progressed.

** Ben himself takes a massive level in Jerkass in the third season of ''Alien Force''.

* It's safe to say that {{Flanderization}} has engulfed the cast of ''WesternAnimation/FamilyGuy'' so intensely that it's easier to list characters who haven't undergone this trope to some extent. The best instance of an inversion is Stewie, who TookALevelInKindness to the point where he's now the most likable character on the show. (Relatively speaking, of course; he used to be ''evil'', and nowadays he's just an asshole.)
** Peter Griffin, after his show was UnCanceled, goes from being a basically-good JerkWithAHeartOfGold to more of a full-on, often malevolent {{Jerkass}}.

** Even Brian followed this route to the point where he got [[TheReasonYouSuckSpeech told off]] by ''[[TheHedonist Quagmire]]'', of all people.

** Quagmire reached this level by his [[SitcomArchnemesis relationship with Brian]], such as his [[{{Hypocrite}} hypocritical]] rant against Brian in "Jerome is the New Black" (as said above), [[NoHoldsBarredBeatdown beating the tar out of him]] after he [[spoiler:unknowingly had sex with his just-transitioned dad]] in "Quagmire's Dad", giving Brian another rant for mistaking his cancer-ridden niece for a boy in "Road to the North Pole", and [[JerkWithAHeartOfJerk faking an acceptance of his apology and running him over]] in "Tiegs for Two".

* Bender of ''WesternAnimation/{{Futurama}}'' fame has always been a {{Jerkass}} of sorts, and that doesn't even take into account the fact that he's a criminal for numerous cases of thievery alone. Still, he isn't above his PetTheDog moments and can feel guilt for some of his harsher actions, and that doesn't even take into account what [[TrueCompanions Fry and Leela really are to him]]. Later episodes, particularly in the show's UnCanceled era, increased his sociopathic tendencies however, where he goes so far as to commit outright murder and at one point even damns his own son to robot hell, something that disturbs [[EvenEvilHasStandards the Robot Devil]].

** An episode in which Arnold learns karate after being mugged saw Arnold himself doing this, lashing out physically at even the slightest provocation or just to show off what he could now do. ''[[LovingBully Helga]]'' is horrified by this.

*** Fluttershy herself takes multiple levels in jerkass throughout the episode as a result of self-confidence lessons working out far too well. By the end, she's gone from her usual meek and passive self to a vicious, aggressive person who casually delivers deep personal insults and picks fights over any slight real or imagined.

** Rainbow Dash's Level in Jerkass deconstructs this, since it led to several repercussions and Aesops that stuck to her character and led to her having to [[TookALevelInKindness take levels in kindness]] by Season Three.

* A large amount of the cast of ''WesternAnimation/TheSimpsons'' have evolved this way as the show has [[DenserAndWackier leaned into zanier]], more satirical, territory. The most infamous case of this occurred with Homer Simpson: While he was always selfish and moronic, he initially had some level of goofiness and kindness to offset this. When Mike Scully took over (in season 9) and shifted the show into more of an overt comedy, his selfishness and sociopathy went to [[Series/StarTrekTheNextGeneration Q-esque levels]]. When Al Jean took over, he toned down the character into his early-era goofiness, although he reverted to his infamous Scully-era persona after Matt Selman stepped in as co-showrunner.

** Even Kyle arguably got this. In "Douche and Turd" he almost has ''[[WithFriendsLikeThese Stan]] killed by Puff Daddy'' [[ItsAllAboutMe so he can get his vote for his candidate]] and then gets even madder at him for voting for Cartman's candidate, and "Fatbeard" shows him willing to send Cartman's entire pirate crew (including classmates such as [[ButtMonkey Butters]] and Clyde) to their death in Somalia.

** Mr. Krabs, depending on the episode be it the first or the later seasons, varies from a decent, if money-obsessed, businessman, into a horrendous boss who has a MoneyFetish and ([[KarmaHoudiniWarranty almost]]) always [[KarmaHoudini gets away with his crimes]]. By season 12, he's mentioned to bribe the health inspector to avoid failing inspections, and only cares about [=SpongeBob=] because he makes him money.

** Squidward changed from a {{Deadpan Snark|er}}ing JerkWithAHeartOfGold who simply disliked [=SpongeBob=] and Patrick's childishness into a full-on {{Jerkass}} more openly hostile towards them, often without provocation. Possibly {{justified|Trope}}, considering the fact that [=SpongeBob=] and Patrick also took considerable levels in Jerkass (especially the latter).

** While not as much as Mr. Krabs, [=SpongeBob=] can also shift into {{Jerkass}} territory at times. A good example of [=SpongeBob=] being more of a jerk comes in "A Pal for Gary". Worried that Gary is lonely, he gets a new pet (by stealing it) but ignores the seller's warning it hates other pets, which constantly ruins Gary's life among with berating and punishing him for being unsupportive of it. When [=SpongeBob=] sees Puffy Fluffy eating Gary, he says that Gary should put Puffy Fluffy down. [[LaserGuidedKarma Then Puffy attempts to eat him]] and when Gary saves him, [[UngratefulBastard he scolds him for making Puffy run away rather than thanking Gary]]. Even by the later seasons' standards, that's moronic of [=SpongeBob=], not to mention quite dickish.

** Patrick even more so:

** Star Butterfly was pretty stubborn and rough during the first season, but Season 2 displays her as being more selfish than earlier on.

* WesternAnimation/StevenUniverse is a rarely more tragic case. As ''[[WesternAnimation/StevenUniverseFuture Future]]'' progresses, Steven's buried resentment starts to come up more and more due to his ShellShockedVeteran stresses, which are themselves exacerbated by Steven not having any more major problems to distract himself with as he tries to handle the changes in his life. Fortunately, after his issues are resolved (or at least are being dealt with) in the series finale, Steven regains his kind disposition, and thoughtfully gives his loved ones gifts before [[ButNowIMustGo leaving Beach City]].

** The case can also be made for Courtney after her return to the show in season two. She went from being a slightly stuck-up and haughty girl who was still civil enough to be the TeamMom, to a scheming, spoiled princess who uses her lawyers to cheat her way to numerous advantages on the show. She basically transformed from a significantly better version of [[RichBitch Heather]] to a straight up {{Expy}}.

** Catra starts out with an obvious mean ''streak'', but after Adora's departure from the Horde, it begins to consume her: she starts taking a sadistic pleasure in hurting Adora, berating her underlings and so on. It reaches its peak in season 4, as she copes with repressed guilt over [[spoiler:the whole portal thing]] by bullying everyone around her, demanding absurd workloads, hurling verbal abuse at Scorpia and so on; [[spoiler:she manages to drive ''at least'' four people out of the Horde, including the previously very loyal Scorpia, via MistreatmentInducedBetrayal]].
** In season 4, between the stress of [[spoiler:becoming Queen]] and the breakup of the Best Friends Squad, Glimmer's negative traits start to take over. She becomes jealous and resentful of Adora, seeing her attempts to take the lead as challenges to Glimmer's authority [[spoiler:and blaming her for Angella's death]]. Her ruthless streak, hinted at in earlier episodes, comes to the forefront, and she starts taking bigger risks, using Adora as a decoy, lashing out at her allies, and so on. Even at her worst, though, she still keeps ''some'' positive traits; she seems genuinely friendly towards [[spoiler:post-HeelFaceTurn Scorpia]], for example, and doesn’t treat everyone like complete crap like Catra does.

* Eustace from ''WesternAnimation/CourageTheCowardlyDog'' definitely fits this trope. He has never been nice to Courage the slightest bit no matter what the dog does for him. The episode "Ball of Revenge" is where Eustace was at his worse. He finally attempted to get rid of Courage by hiring the dog's past foes to ''kill him'', which is sad since [[UngratefulBastard Courage had actually gone through all the trouble to save him in many other episodes]].

** Cosmo from season 4 onwards.

** Timmy's dad surely began showing signs of this as the series went on.
** Timmy's mom did, too. The two used to just be overworked. Now they're straight up {{abusive|Parents}}.

** Quagmire reached this level by his [[SitcomArchnemesis relationship with Brian]], such as his [[{{Hypocrite}} hypocritical]] rant against Brian in "Jerome is the New Black" (as said above), [[NoHoldsBarredBeatdown beating the tar out of him]] after he [[spoiler:unknowingly had sex with his just-transitioned dad]] in "Quagmire's Dad", and [[JerkWithAHeartOfJerk faking an acceptance of his apology and running him over]] in "Tiegs for Two".

* Nani from ''WesternAnimation/LiloAndStitch'' started out as a compassionate older sister with justified anger issues due to the stress of looking for a job to support herself and her younger sister, and [[JerkassHasAPoint does have a point at times to punish Lilo]]. In ''[[WesternAnimation/LiloAndStitchTheSeries The Series]]'', she became a more short-tempered and ruder {{Jerkass}} who grounds Lilo and Stitch for little reasons, [[DisproportionateRetribution with little point whatsoever, like running around the house]]. She doesn't care if Bonnie and Clyde are on the loose and refuses to let Lilo and Stitch to go outside to catch them.

* ''WesternAnimation/MickeyMouse2013'' makes WesternAnimation/DonaldDuck, normally a JerkWithAHeartOfGold, a straight-up {{Jerkass}}. The most infamous example is "[[Recap/MickeyMouseS2E19BroncoBusted Bronco Busted]]". The shorts in the later seasons, mostly the 2016 holiday special, Duck The Halls, managed to tone down his obnoxiousness and reverted Donald back to his usual JerkWithAHeartOfGold status.

*** As did the entire population of Ponyville, apparently. In this episode they're a bunch of callous bastards who try and scam Fluttershy, bump her out of lines and yell at her when she protests, and insult her for asking if they'll move their carts so she can pass by. In fact, pretty much everyone in the episode on the receiving end of Fluttershy's jerkassery [[KickTheSonOfABitch had it coming]], and she only officially went too far when she unleashed her fury on Pinkie Pie and Rarity which brought them to tears.

* One of the main complaints about ''WesternAnimation/TeenTitansGo'' is the fact that the main team ([[TokenGoodTeammate excluding Starfire]]) has undergone this.

* ''WesternAnimation/{{Kaeloo}}'': At the beginning of the show, Stumpy starts out as a kind and well meaning but stupid kid. In Season 2, he starts to become slightly meaner, and in season 3 he's almost as much of a jerk as Mr. Cat, and enjoys torturing people for no reason other than his own amusement.

** Steve himself basically became a complete brat as a result of his Flanderization during the 8th/9th seasons. It got to the point where the plot for "Morning Mimosa" was about him going "F**k you!" to ''his own mother'' with absolutely zero qualms whatsoever.

* ''WesternAnimation/TotalDrama'':

** Dave from ''Pahkitew Island'' is a rare case of this happening '''in the very season he debuted in'''. As the season progresses, his his frustration at his teammates causes him to go from an OnlySaneMan [[JerkWithAHeartOfGold with a heart of gold]] to an EntitledBastard towards Sky. He gets worse in the finale where he finds out that Sky already has a boyfriend.

** WesternAnimation/DaffyDuck was introduced as a fun-loving nut, becoming more stable and ambitious by means of CharacterDevelopment, as well as more embittered and obnoxious in personality, often acting as an [[IneffectualSympatheticVillain antagonist]] to WesternAnimation/BugsBunny. His cruelty was taken to extremes with his pairings against 'WesternAnimation/SpeedyGonzales in the DePatie-Freleng era. For instance, in ''WesternAnimation/WellWornDaffy'', Daffy is hellbent on keeping Speedy and a friend from a desperately needed well for no other reason than for pure maliciousness, and then attempts to destroy it for absolutely no reason except to be mean.