Because you like Sweeney Todd in Sweeney Todd: The Demon Barber of Fleet Street
The Grinch's heart is just too small to appreciate Christmas. See them in Dr. Seuss' How the Grinch Stole Christmas.
A born psychopath, don't expect Michael Myers to understand the difference between right and wrong. See them in Halloween.
Count Olaf is a traveling actor, except he can't act and his homicidal tendencies make finding work pretty difficult. See them in Lemony Snicket's A Series of Unfortunate Events.
A cursed pirate captain, Barbossa is greedy, vengeful, and surprisingly cheeky. See them in Pirates of the Caribbean: the Curse of the Black Pearl.
Louis de Pointe du Lac is wanting to find a way of living that doesn't make him miserable. See them in Interview with the Vampire: The Vampire Chronicles.
This master marksman may be a villain, but Deadshot's motives aren't quite as selfish as they seem. See them in DC Extended Universe.
Gomez Addams fills his days with ghoulish and ghastly forms of recreation, enjoying life and all its pleasures to the fullest. See them in The Addams Family.
Peter Venkman's "research" projects are designed to get undergraduate students to sleep with him. Though it turns out he can bust ghosts. See them in Ghostbusters.