Adaptational Jerkass

While some adaptations make a character nicer, this is the opposite, making a character more of a Jerkass than they were in the original work

While there is some overlap with Adaptational Villainy, the key difference is that a character isn't necessarily villainous. It can be a hero who was made into an Anti Hero, or a villain who was Affably Evil is now Faux Affably Evil.

Compare Took a Level in Jerkass.

Anime and Manga

 * The Pokémon anime's first season wasn't above giving the Gym Leaders a bit of edge to their personalities. They're fairly nice and personable in the games,, but here you get to see Lt. Surge act like a schoolyard bully, calling his opponents babies while his Raichu sadistically beats their Pokémon so badly that they're sent to intensive care. Blaine's also okay with endangering his opponents' Pokémon by making them fight him in an active volcano, Erika will go so far as to ban people from her Gym just because they insulted the perfume she sold at her store, and even Brock and Misty can be real jerks when the situation calls for it. Then there's Sabrina, but she's a straight case of Adaptational Villainy.

Fan Works

 * Gilbert from Fire Emblem: Three Houses is an emotionally stunted man and a stern absent father who nonetheless loves his daughter Annette dearly. But fics that demonize him such as The Emperor and the Goddess and To Those Who Are Never Coming Home make him an abusive bully who shames her no matter what she does, with the latter fic having him slutshame her due to having a child out of wedlock.

Film

 * Death Note: While Light has always been a murderous Villain Protagonist, the live action film series makes him even worse. He becomes more evil more quickly than either the anime or manga, to the extent he's perfectly willing to personally kill his own father to prevent the Death Note from being organized.
 * The oft-mocked scene from Harry Potter and the Goblet of Fire where Dumbledore, instead of calmly asking Harry if he had placed his name into the Goblet, immediately starts yelling and interrogating him.

Web Original

 * Stupid Mario Brothers has several examples, all Played for Laughs:
 * Far from the happy-go-lucky hero of the games, Mario here is a selfish Lazy Bum who does such things as refuse to cut his vacation short to rescue Peach from Bowser again, on top of.
 * Princess Peach of the game series is a Nice Girl through and through. This Peach is a whiny, nagging Spoiled Brat.