Pygmalion Snapback

Human nature is a strange, fickle thing. One man's virtues are another's "deadly sins". It should come as no surprise that The Schemer or another morally domineering character would take it upon themselves to "improve" the lot of their fellow man by giving them a Pygmalion Plot makeover.

Rarely is this effort altruistic; even rarer is the cognizance (much less consent) of the Galatea. If the effort is made for greed, fueling a plot, or out-and-out hubris, the results will never be good... for the Pygmalion.

Y'see, changing others to suit your needs or ideals of how they should be is an irreducibly selfish and prideful act, and often completely ignores the wishes and welfare of the recipient. Sure, sometimes the Galatea will actually be objectively made better off... but many didn't ask for it, didn't want it, or (if they did), realize they aren't as happy as they thought they'd be.

These changes will be subject to Snap Back as the character returns to their original self (with perhaps one or two hard learned habits being retained) and the benefactor will get some amount of karmic backlash for their hubris. At the very least, they'll get a Calling the Old Man Out either by the Galatea or a friend of theirs. On the romantic spectrum, the Love Martyr trying to change their abusive hubby this way is in for a nasty surprise.

This is often exaggerated when the Pygmalion character has Green Rocks that can do the above quickly and easily without even a Training Montage. They'll discover the new photo negative personality is most definitely worse than the original, often either obviously evil, full of anger, hyper competent, a Suspiciously Similar Substitute to the Pygmalion, or all of the above. In the end, We Want Our Jerk Back. Depending on the tone of the episode or show, the story may or may not come with the Aesop of being thankful for what you have.

Compare Flowers for Algernon Syndrome, where the change is something Galatea wanted, but is still snapped back. Often done to the Weak-Willed. A common after effect from using a Mirror Morality Machine. Frequently a way to enforce Status Quo Is God.

Anime/Manga

 * In Beauty Pop, the main character gives the Shrinking Violet a make-over — making her lose her glasses, putting her in trendy clothes and pretty make-up, and giving her a new hair-do. The girl keeps it just long enough so she can taunt a boy who rejected her for being plain. In the next chapter, she put the glasses back on and put her hair in braids again, saying she felt weird otherwise.

Live Action TV

 * The episode of The King of Queens "Jung Frankenstein". Initially, Carrie sends Doug to a therapist to control his eating (which he isn't too thrilled about). When that goes well, she secretly convinces the therapist to get rid of Doug's other vices (that's how she sees it). Needless to say, when he finds out, he's furious. As he puts it by the end of the episode, "Well why don't I strap a suggestion box to my ass? It'll save you the trip."
 * Star Trek: Voyager. Captain Janeway gets interested in holographic character Michael Sullivan in the "Fair Haven" program, and starts tweaking his program to make him more to her taste. Eventually she gets called on it by Voyager's doctor (also a hologram) and eventually shuts off her access to Michael's program so she won't be tempted to make more 'improvements'.
 * The major moral conflict in Stargate Atlantis and the "Michael" subplot. Basically, the human heroes of the show find a drug that turns a Wraith human, and causes it to lose its memories. However, the turned Wraith must keep taking it or the transformation is reversed. The Wraith they try it on (nicknamed Michael), is pissed when he finds out what they did to him, and becomes one of the most dangerous recurring villains in the series because of it. This is by far the biggest case of Moral Dissonance in the show, with the fans, Michael, and even various members of the heroic cast screaming What the Hell, Hero? at the ones who came up with it.

Literature

 * The trope namer is the stage production Pygmalion by George Bernard Shaw, adapted into musical form with My Fair Lady. Containing the aformentioned pygmalion as represented by the incorrigible Henry Higgins (with his grand knowledge of accents, a novelty in turn-of-the-century England) who attempts to change the cockney Liza Dolittle into a well-bred, well-spoken English lady by correcting her common drawl. He succeeds but then discards his creation, much to Liza's great consternation, which is where the narrative tension arises in the second half of the play.
 * In The Dresden Files, this is shown to be the eventual result of any kind of tampering with someone's mind. Eventually, the true personality reasserts itself, leading to at best a backlash  or a far worse reaction as the psyche shreds itself trying to turn back to normal
 * The Transformers short story "Redemption Center" in the anthology Transformers Legends involves Starscream getting amnesia while in Autobot custody. Optimus refuses to reprogram him, even though it would now be simple, because it would be unethical; but he agrees there's no harm in simply showing him what life is like in a society where everyone isn't constantly being a Jerkass to each other like the Decepticons. When 'Screamer's memory finally returns, he chooses to

Western Animation
"Moe: There's just one thing I don't get, though. When my face was crushed, why'd it go back to my old face? I mean, shouldn't it have turned into some kind of third face that was different? Heh. Don't make no--(end credits abruptly cut him off)"
 * In Beast Wars, Megatron managed to switch Rhinox into an evil Predacon. Joke was on Megatron, as Rhinox was far more competent than your typical Starscream and nearly deposed him!
 * On The Flintstones, Wilma and Betty managed to completely change Fred and Barney's personalities on at least two occasions. The first time (by enrolling them in "charm school"), they got bored and tried to change them back. The second time (through subliminal messages in their sleep), Fred and Barney found out what their wives had done and took revenge.
 * Batman Beyond: Return of the Joker: Joker gives him a personality makeover in his own image. "J.J." ends up snapping back just enough
 * One episode of Bionic Six combined this with In the Blood. The good professor wiped his evil brother Doctor Scarab's memory with the best of intentions to reform him, and was re-teaching him basic skills... and hard sciences. This new Scarab was more competent, smarter, and managed to hook up with his old goons to do a near successful attack on the Bionic Six. So, this trope works both ways for the good and evil.
 * On one episode of Pinky and The Brain, Brain makes Pinky smarter, hoping that he will now be helpful in his plans for world conquest. But Brain finds that Pinky is too smart, always pointing out the flaws in Brain's plans. To restore balance, Brain applies the same process in reverse and makes himself dumb. Unfortunately, so has Pinky.
 * In Dexter's Laboratory, Dexter once attempted this on Dee Dee, as he was tired of her destroying his lab, via a brain transplant. She turned out to be far more competent than him at science.
 * In another episode, Dee Dee tries to loosen up Dexter, and once converted, he starts destroying his own lab, violently and maniacally. He also proceeds to wreck Dee Dee's own things. Needless to say, Dee Dee takes destruction of her property way worse than Dexter takes destruction of his.
 * In the Invader Zim episode "GIR goes crazy and stuff", Zim gets fed up with his sidekick GIR's insane behavior and tinkers with his behavioral modifier to lock him in "serious mode". It succeeds... and then GIR starts questioning Zim's methods because they are stupid and ineffective. In the end, after trying to accomplish the mission goal himself as well as trying to eliminate Zim, he is restored to his usual stupid, non-threatening self.
 * In Goof Troop, Pete once hypnotized Goofy to turn him into a ruthless car salesman like himself. The problem was that Goofy's cluelessness persisted, and caused Pete no end of trouble, including stealing a armored car to sell on the lot, and robbing the policeman who came to investigate. In the end, Pete hypnotizes Goofy back to his old self.
 * Spoofed in Gotham Girls. After Poison Ivy uses pollen that "changes the victim's moral outlook", Batgirl becomes a criminal that joins Ivy and Harley Quinn on a crime spree. Harley, however, quickly feels overworked, and she decides that Batgirl was nicer before the personality shift. Of course, after Harley gives Batgirl the antidote, Batgirl returns to her normal law-abiding criminal-chasing self and immediately captures Harley and Ivy.
 * Chowder: Tired of his stupidity, Mung Daal creates a dish that makes Chowder very smart. At first, the audience expected to see Chowder's smartness becoming intolerable for Mung Daal, but this was subverted by having Chowder realizing that he's a cartoon character in a TV show. Using his newfound powers, he changes the show into a boring educational program. Realizing that this change made things worse, Chowder yanks his new brain out of his nose and smashes it, effectively deleting the show altogether.
 * Duck Dodgers got this makeover thanks to one of Ignacius' inventions. The new Dodgers not only became hyper-competent but even better than everyone else. Then he tried to pull a Pygmalion Plot on the whole Earth, because it didn't live up to his expectations. It could easily have been permanent, as it took all the effort from I.Q., Cadet, Marvin and the Queen to get him back to his old self.
 * Altruism example! In the My Little Pony Friendship Is Magic episode "Green Isn't Your Color", Fluttershy agrees to model some of Rarity's dresses for the photographer Photo Finish, who eds up takes a shine to Fluttershy and doesn't care a slap about the dresses. Rarity spends the entire episode encouraging Fluttershy to go be a rich and famous model because she feels guilty about envying Fluttershy's success and wants to be a supportive friend. Fluttershy, for her part, hates the attention, and they're both bitter that with Photo Finish eating up Fluttershy's time, they can't hang out anymore. Twilight Sparkle spends the entire episode being confidant to them both, but sworn to secrecy for the sake of one another's feelings, and nearly loses her marbles not saying the two sentences that would fix the problem.
 * Lampshaded and spoofed in The Simpsons episode "Pygmoelian": Moe has plastic surgery to become handsome and lands a role on a soap opera. Near the end of the episode the wall of a set falls on his face, and in the next scene we see he's back to normal. The last lines of the episode: