Because you like The Grinch in Dr. Seuss' How the Grinch Stole Christmas
C is for cookie, and that's more than good enough for him. See them in Sesame Street.
Sideshow Bob is a bitter ex-performer who was forced to do inhumane stunts for slapstick comedy. Now he's exacting revenge on his former boss, a clown. See them in The Simpsons.
Buddy Pine is an unhinged superfan of superheroes using technology to take down his idols. See them in The Incredibles.
Charlie Bucket may be down-on-his-luck, but his spirits are always sky high. See them in Charlie and the Chocolate Factory.
A monstrous pirate captain, Davy Jones is quite literally heartless. See them in Pirates of the Caribbean: the Curse of the Black Pearl.
Donkey is proof that if you're annoying enough you can change the world; he's the reason that his friend Shrek does, well, anything. See them in Shrek.
This lab mouse has one thing on his huge brain: trying to take over the world on a nightly basis. See them in Pinky and the Brain.
N'Jadaka is a righteous man with a violent agenda. See them in Marvel Cinematic Universe.
Ultron is security software turned evil mastermind. See them in Marvel Cinematic Universe.
Once a handsome prince, the Beast is now a grumpy, furry, monster. It's hard to pinpoint which mammal he resembles the most. See them in Beauty and the Beast.