Flanderization

Flanderization is the act of taking a single trait from a character and exaggerating and amplifying it more and more over time until it completely consumes the character. Most always, the trait/action becomes completely outlandish and it becomes their defining characteristic. Comedy shows are usually the ones to suffer this, due to the writers doing anything they can to get a cheap laugh from the audience, even if it means sacrificing a character's personality. Either there are out of character personalities that are counted as against the characters we known in love, or there are personalities that will make you have no choice but to lose all of your respect you would have had for all the characters.

Although, flanderization doesn't always make the characters turn out awful. Some flanderization can make them more funnier and likable. It depends on how the character is flanderized.

Notable victims of flanderization

 * 1) Ned Flanders (The Simpsons; the trope namer; went from merely enjoying going to church to being obsessively religious and overly nice, and then later an obnoxiously intolerant bigot who will lash out at anyone that doesn't support Christianity)
 * 2) Moe Szyslak (The Simpsons; became the show's punching bag, even before he was the show's punching bag, he was the main punching bag whenever he gets prank called by Bart)
 * 3) Homer Simpson (The Simpsons; became a selfish and sometimes psychopathic moron)
 * 4) Marge Simpson (The Simpsons; turned into an overprotective mother who's no fun at all, what is completely against her character, this happens in the episodes where the episode is disliked by fans or is just plain bad)
 * 5) Bart Simpson (The Simpsons; turned into a borderline sociopath)
 * 6) Lisa Simpson (The Simpsons; became a know-it-all SJW, which is far too against her character)
 * 7) Maggie Simpson (The Simpsons; became a flawless Mary Sue)
 * 8) Donald Duck (Disney Cartoons; the trope codifier; became the meanie we all know today)
 * 9) Garfield (The Garfield Show; became an unlikable slob)
 * 10) Jon Arbuckle (The Garfield Show; became an idiot)
 * 11) Nermal (The Garfield Show; became a jerk)
 * 12) Spongebob Squarepants (Spongebob Squarepants; Seasons 6-8; became an obnoxiously happy moronic idiot)
 * 13) Patrick Star (Spongebob Squarepants; Seasons 4-8; he suffered two flanderizations; he started out as kind of slow but fairly intelligent, but then around the end of the first season, he became more stupid and immature and eventually his stupidity became his main, defining trait; then, in seasons 6-8, his second flanderization started where he essentially became brain dead, with his actions becoming dangerous at times, and while Patrick had his jerky and antagonistic moments in earlier seasons, these moments pretty much became a major part of him in these seasons, and in season nine onwards, he finally got better after years of complaints from fans and critics)
 * 14) Squidward Tentacles (Spongebob Squarepants; Seasons 6-8; became more of a butt-monkey/punching bag than he already was, with his hatred of SpongeBob and Patrick increasing to the point where it's shown a few times that he even wants him/them DEAD; his temper also shortened considerably)
 * 15) Mr. Krabs (Seasons 6-8; turned into an even bigger black-hearted and self-serving greedy monster who, in one episode, terrorized Plankton to the point where he attempted suicide (yes, seriously) and Mr. Krabs just brushed it off like it was nothing; his love for money also became over-exaggerated)
 * 16) Scoop (Bob the Builder; became a careless idiot in the Bob the Builder reboot)
 * 17) Muck (Bob the Builder; became a retard in the Bob the Builder reboot)
 * 18) Eric Cartman (South Park; became an absolute villain rather than just a jerk; not to mention, his bigotry used to be only targeted toward Kyle)
 * 19) Randy Marsh (South Park; became a paranoid manchild)
 * 20) Bloo (Foster's Home for Imaginary Friends; started out as being protective over and caring of Mac in the pilot whilst being only slightly mischievous and then became a "jerk with a heart of gold" type of character in the first season, but then eventually he lost the "heart of gold" part and just became a full-blown, straight-up, outright a-hole whose jerkiness kept getting worse and worse as the show went on until he finally started leveling off around the end of the series)
 * 21) Flippy (Happy Tree Friends; received a repetitive behavior where his PTSD influenzed in almost every appearance he made. This made the moments of him killing other characters while delusional progressively boring)
 * 22) Splendid (Happy Tree Friends; similar to Flippy, received a repetitive behavior where accidentally kills characters he rescues, often by his lack of common sense)
 * 23) Optimus Prime (In the Michael Bay Pentalogy of Transformers, he proved he was a psychotic murderer killing machine in Transformers 2: Revenge of the Fallen)
 * 24) Thomas the Tank Engine (Thomas and Friends; Seasons 9-16; Same as Spongebob Squarepants)
 * 25) Percy The Small Engine (Thomas and Friends; Seasons 8-16; became a retarded moron like Thomas)
 * 26) Edward The Blue Engine (Thomas and Friends; Seasons 8-16; became an old paranoid wimp who worries about everything way too much and is no fun at all, unless he is in character depending what episode it is)
 * 27) Henry the Green Engine (Thomas and Friends; Seasons 8-16; became a paranoid coward, wimp, and a moron)
 * 28) Gordon The Big Engine (Thomas and Friends; Seasons 8-16; became a punching bag and also a pompous killjoy, but in a bad way, even when it comes to him tempting fate or getting his comeuppance, "Bust My Buffers!" is one of the episodes where Gordon just gets tortured and Diesel, 'Arry and Bert don't get punished or scolded for their actions)
 * 29) James The Red Engine (Thomas and Friends; Seasons 8-16; became a pretentious and complete jerk about his red paintwork without even thinking of others in the slightest, but in "James Gets a New Coat" (which was a clever episode), he gets his comeuppance for boasting about his red paint so much)
 * 30) Toby The Tram Engine (Thomas and Friends; Seasons 8-16; same with Edward and Henry)
 * 31) Emily The Stirling Engine (Thomas and Friends; Seasons 8-16; became a bossy, nagging, short-tempered bitch, and also turned to a really idiotic moron after episodes where we see her such a kind and friendly engine like Edward, this is an example of making your characters worse if flanderized, why flanderize them to an even worse personality? That is two flanderizations in one show! How can you make those personalities make Emily more unlikable? HiT Entertainment should have sticked to giving Emily the same personality they had in season 7, what did they do? They screwed it up, BAD!)
 * 32) Skarloey The Little Old Engine (Thomas and Friends; Seasons 9-12; became a scaredy engine over everything, but got better in Season 16)
 * 33) Rheneas The Gallant Old Engine (Thomas and Friends; Seasons 9-12; became a killjoy)
 * 34) Sir Handel The Blue Engine (Thomas and Friends; Seasons 10-16; became an engine who often breaks down and also messes up sometimes, "Sir Handel in Charge" is an example of this)
 * 35) Peter Sam The Green Engine (Thomas and Friends; Seasons 9-16; became a moron)
 * 36) Rusty The Little Diesel (Thomas and Friends; Seasons 9-11; became too bossy to even be helpful like Emily)
 * 37) Belle the Firefighting Engine (Thomas and Friends; Season 15; her personality was wasted in the infamous "Big Belle" episode)
 * 38) Peter Griffin (Family Guy; Became an insane, rude, selfish, and egotistical person)
 * 39) Lois Griffin (Family Guy; Season 7-present; became a sex-crazed, abusive short-tempered wife)
 * 40) Meg Griffin (Family Guy; Seasons 6-14; became a punching bag until Season 14)
 * 41) Chris Griffin (Family Guy; Season 7-present; became a character going in full idiot mode)
 * 42) Brian Griffin (Family Guy; Season 7-present; his entire personality now amounts to being a "liberal", and became a complete jerk and got even worse when he came back)
 * 43) Glenn Quagmire (Family Guy; Season 7-present; became not just a pervert, but an implied child molester)
 * 44) Ren Hoek (Ren and Stimpy: Adult Party Cartoon; Same as Optimus Prime)
 * 45) Ash Ketchum (Pokémon the Series: Sun and Moon; Proved that he is annoying as hell and proved that he would never age; Ho-Oh is still not an excuse)