Walking Dead had a blonde female character who had good morals and was REALLY wise, saying stuff like,"If it doesn't feel morally right, just don't do it," to changing her to a brazen hussy. Sad really. Even Fans pointed out the Writers really messed up her character REALLY badly.

Max from George Lopez started off snarky and funny as a 10 year old, cut to 14 and he was a pervert hitting on a 20 year woman he knows is his FIRST cousin(Not even something like a Step cousin):eek: He also tried to have sex with a Woman who he knows had been in Prison for having sex with another underage boy. Luckily, she made him get out of her house and didn't have sex with him. George was appalled and was like,"Max had a Police been driving by, you could have landed her back in prison for something she didn't do!"

Chelsea from That's So Raven started off as normal and funny, but Season 2-4, she was an Idiot. I honestly thought EDDIE was going to be the dumb one. In Season 1, Raven and Chelsea made it clear that Eddie had the wrong information and Raven was like,"You're Uncle Louie died this morning." Eddie was like,"I don't have an Uncle Louie." Raven was like,"I must have the WRONG information!" Chelsea also said,"Raven has the WRONG information!" And Eddie still couldn't read between the lines that he had the WRONG information! In the same episode, Eddie was studying for a Spanish test and couldn't tell that Atun was clearly tuna. He put the Atun flashcard on a milk carton, what an IDIOT! :rolleyes:

Kevin Arnold from The Wonder Years went from the protagonist to a loser after Neal Marlens and Carol Black left as writers. While I have said thousands of times on these boards the show should never have been canceled, the original writers could have come back to the show to turn Kevin back around--and given it a better shot at being #1 in the Nielsen ratings.

Not to sound like a broken record, but Albert Ingalls from Little House on the Prairie was changed for the worse after the writers made him responsible for killing two characters. I don't know why they did it, but there was no fixing his character afterwards.

All the Connor men from Roseanne were ruined, until the reboot reset everything. They made the granddad a flat out racist, Dan sort of racist and DJ a racist in training. The writers also turned him into a jerky dad who causes Becky to go off the rails. The episode that really messed him up was when he gave Becky the silent treatment for using his motorcycle. His character became so screwed that the show didn't even think twice about killing him off in the finale.

The worst character change, though, was Seymour Skinner from The Simpsons. He was supposed to be this uptight mama's boy who'd never had sex but and was a complete dork, but then there was the episode that made it so that he had been a cool greaser and only pretended to be Seymour Skinner after the real one died.

Not a sitcom at all, but Piper Halliwell from Charmed started off as sweet and nice to being a bossy bitch in Season 4-Season 8...:/

One of the biggest changes ever was Jonathan Harris as Dr. Smith -- from seething, scheming villain to nattering ninny man-child -- but one might classify it as a brilliant move.

Rachel in Netflix's Ozark.

Season 1, she was seen as normal, a character with suspicion.
Season 2, Writers made her messed up with an alcohol abuse issue (not seen in Season 1) and trapped into making poor decisions and an incident, then wrote her out of the story for a full season. Sure, anyone can get into alcohol abuse or had one prior. How convenient. Little explanation or reason that made sense from S1 to S2 for it.
Season 4, She returns, and more like Season 1. Writers likely realized what a dumb plot change for her was in Season 2.

She was a good character/actor who should have been there for Season 3 and probably not changed that way from Season 1 to 2.