There are subjectives, and then there are these. While you may believe a work fits here, and you might be right, people tend to have rather vocal, differing opinions about this subject. Please keep these off of the work's page.
Dethroning Moment: Foster's Home for Imaginary Friends
We wish there was a secret door to put these episodes behind...
No Real Life examples including Executive Meddling. That's just asking for trouble.
No ALLCAPS, no bold, and no italics unless it's the title of a work. We are not yelling the DMoSs out loud.
Triassicranger: The episode "The Big Cheese". The scene that kicked me in the teeth was when the tv crew comes to film Fosters, only to find it is a wreck (thanks to everyone joining in with Cheese's dancing), proceed to give Fosters negative publicity, cause Eduardo to burst into tears because they won't stop filming him without his shorts on, and Cheese hogging up all the limelight including the closing credits reel. It did not help that Bloo acted like a complete jerk without motivation, as opposed to earlier seasons (such as the one where he treats the puppies badly after they divert attention away from him and his "time machine"). Yes I know there's no excuse for bad behavior but at least Bloo had motivations.
Ub3r D4n: Okay then, I guess on behalf of everyone on the Fosters fansite Never Forgotten, I have to add the end of "The Little Peas" as the most widely recognized Dethroning Moment of Suck for the show. Not only is it a retelling of the aforementioned episode "The Big Cheese" (which is not well liked either), but focuses on an OC and has little to do with the main cast at all. The real kicker is the end, where it turns out the one good thing Frankie managed to do in "The Big Cheese" (where she was pretty much tortured the whole way through) turns out to be the idea of the OC's, not hers. Not only was it a tremendously poor episode (by the show's standards, at least) but it severely tainted my memory of earlier episodes.
Thomas Veggie Drama Fan: While "The Big Cheese" was indeed terrible (this coming from somebody who hates Cheese most of the time) "The Little Peas" actually made that piece of crap even worse for the big reason you pointed out.
Mad Man 400096: "I Only Have Surprise For You". In it, Mac tries to avoid having yet another embarrassing birthday party. So what does the rest of the house do? They all take a level in jerkass (except Eduardo, who just did what the invitations told him) by making him feel miserable but faking a little boy's birthday party, having him unknowingly obliterate it (thinking it was his own) and then reveal the whole plan. While having Bloo do this is usual, him being the Jerk Ass he is, everyone else suffered a major case of Character Derailment just by taking part (Except Eduardo, who just did what the invitations told him).
RAD Dman: This troper's DMOS for Foster's (which, in my opinion, had so many of them that they made me forget most of the good episodes) is "Everyone Knows It's Bendy". This episode has the main group of imaginary friends (Bloo, Wilt, Coco, and Eduardo) squaring off against a new guy named Bendy who causes trouble but uses crocodile tears and kissing-up to make Mr. Herriman and Frankie think it was the guys. First of all, I get why they would think that Bloo did the stuff he was blamed for; besides the fact that Bloo's gung-ho attitude in the episode makes it look like he did it when they come, he's known for being a troublemaker (He's even been in jail!). But Herriman and Frankie have known Wilt, Eduardo, and Coco for a long time and know that they're generally nice and stick to the rules. Why would they believe a stranger they know little about over three long-time friends who usually don't break any rules, especially since the rash of rule-breaking started only when Bendy came in? It's absurd and unbelievable. However, the worst thing about the episode and the one thing that made many fans hate it is that in the end, Bendy wins. Bloo tries to catch Bendy in the act, but the lengths he goes to (his scheme ends in the house being flooded) just to catch Bendy taking a cookie lead to him getting in even more trouble with Frankie and Herriman. There is no comeuppance whatsoever; the good guys lose and the bad guy ends the episode by spraying the camera with a spray-paint can.
RyRodrigo: I was so pissed off after watching that episode and "Fosters Goes to Europe", I stopped watching the series altogether. Those episodes were mean spirited in the worst possible way, and I never felt such an overpowering urge to throttle a cartoon character before. (I'm looking at you, Bendy.)
Shadoboy: "Everyone Knows it's Bendy" was so bad that Lauren Faust actually apologized to the fans for it.
TT 454: Mine would have to be "Squeakerboxxx". I found this episode unnecessarily mean-spirited and in many ways, annoying. The episode involves the gang winning a rubber elephant at an arcade. The squeaking from the rubber elephant becomes tiresome after a while, and Eduardo's disturbing, motherly obsession with it becomes obnoxious. When Bloo breaks this elephant, he has to go and win a new one before Eduardo knows. Due to Bloo's selfishness, he wins enough tickets for the elephant (after suffering several blows to the face due to inaccurately throwing balls at the arcade machine instead or rolling them), but uses them to buy some Dracula fangs. He then goes back to the arcade to try again, but the elephant's been won by a bratty kid, so he challenges her to the same arcade game, which she wins easily. Foolishly, Blue runs away with the elephant anyway, and is knocked out by the kid. Mac, knowing Bloo would fail to get the elephant, has bought a new one. Bloo returns home with the elephant, but for some reason, a panicking Eduardo rushes towards Bloo, making him throw the elephant in the air in fright, and then accidentally swallow it despite having plenty of room to move out of the way. So, the ending is this: Bloo now squeaks like a rubber elephant, and the gang make him be the elephant to compensate for not having one. This episode is painful to watch mainly because it's literally the stupidest possible conflict that could have been resolved if Mac had simply told Bloo to purchase a new elephant in the first place - or, if Bloo had never foolishly broken it by exploiting Eduardo's creepy love of it. It just isn't funny, it's contrived, and the ending is one of the weirdest in the series.
Manwiththeplan: "Fosters Goes To Europe". The ending is so mean-spirited toward Mac, and such an ungodly case of Character Derailment for Madame Foster, that I'm shocked it was able to get past the scripting stage, let alone fully animated and voiced!
fluffything: Agreed wholeheartedly. I can forgive "The Big Cheese", "I Only Have Surprise For You'', and even "Everyone Knows It's Bendy", since those episodes have genuinely funny moments that soften the blow of the bad parts. But this? This is just unforgivable. The European-stereotype imaginary friend is bad enough. But, the worst part is, as mentioned above, the utter OOC behavior of Madame Foster. To elaborate, Madame Foster had stolen the tickets from Mac so she and her elderly friends could go to Europe...Oh, and that aforementioned stereotype-friend goes too. Yup, the episode ends with a blatant disregard for character just to throw in a Shoot the Shaggy Dog moment. Madame Foster is a cool old lady who genuinely cares for Mac and, though she can be mischevious, would never (I repeat, never) do anything so utterly dickish towards someone she treats like family. This is the equivalent of watching someone kick a puppy. Just needlessly cruel.
Psi Basilisk: "Where There’s a Wilt, There’s a Way" is pretty much nothing but the Foster’s Universe cruelly punishing Wilt. The events of this episode start because Bloo asks Wilt to get chips (Not too bad, right?). However, along the way to get chips, everyone Wilt encounters asks him do things for them. The requests start out as harmless quick favors but quickly spiral into insanely unreasonable commands that end with Wilt suffering in some way (be stranded in the ocean, being in jail, etc). After all Wilt goes through he is finally able to get chips for Bloo, however Bloo rudely throws the chips and expects Wilt to clean it up. This leads to the only good part of the episode (Wilt’s “No” Rant). However the episode ends abruptly with Wilt having a door slammed in his face. The worst part is that the writers could have redeemed this episode by making it a full 22 minutes and making the second half revolve around Wilt becoming more assertive. Instead the writers made it only about 9 minutes and dedicated the remaining time to the infamous "Everyone Knows It's Bendy" episode mentioned above.
InTheGallbladder: "One False Movie" had the Show Within a Show "Explorin' Lauren", a parody of Dora the Explorer so embarrassingly exaggerated and unsubtle that it was painful to watch. It's even worse in that its existence was Chekhov's Gun.
Kittens: The ending to "Bye Bye Nerdy". Mac stands up for Bloo when he gets made fun of, and, in the process, gives one hell of a speech. The crowd seem genuinely moved—until Jamez gets smug and calls Mac a nerd. They side with Jamez almost immediately. It was a Negated Moment of Awesome for a character who really deserved a proper one.
heartauthor: "Nightmare on Wilson Way," the Halloween special, was the only episode where the ending left me legitimately rubbed the wrong way. Basically, the episode is about Bloo getting ready for one of his infamous Halloween pranks, while Mac voluntarily locks himself in a room in the house because sugar and him don't mix. However, as the episode goes on, more and more of the Foster's residents begin disappearing...only for them all to come back as zombies who begin chasing Bloo around the house. Desperate and terrified, Bloo is forced to give Mac sugar, causing him to go on a rampage that defeats all the zombies. But then...it's revealed that the Zombie Apocalypse was all a prank by the Fosters' residents to get back at Bloo for all his pranks. Then, to add insult to injury, Frankie tells Bloo that he's in trouble because he set a sugar-buzzed Mac loose on the unsuspecting trick-or-treaters outside. Well, newsflash Frankie: maybe if Bloo hadn't been thinking that he was going to be eaten by zombies, he wouldn't have buzzed up Mac. Okay, considering some of Bloo's Jerkass behavior in some episodes, it does make sense that the Fosters' residents want to get back at him. But Bloo's only crime in this episode? Wanting to pull some Halloween pranks. And then after scaring the crud out of Bloo, they have the gall to say he's the one in trouble at the end of the night? I can't get behind that. I just can't.