Because you like Mrs. Lovett in Sweeney Todd: The Demon Barber of Fleet Street
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.
Thanos is an intergalactic warlord, on the hunt for infinite power. See them in Marvel Cinematic Universe.
Bob Belcher runs a lonely burger joint, and even though his wit is lost on his eccentric family, he doesn't let that faze him. See them in Bob's Burgers.
Greg Heffley will be famous someday, but now he's stuck in class with morons. See them in Diary of a Wimpy Kid.
Egon Spengler prefers collecting spores, molds, and fungus to interacting with people. See them in Ghostbusters.
This bite-sized, power-hungry plankton is determined to uncover the secret recipe for the Krusty Krab burger. See them in SpongeBob SquarePants.
If it were up to her, Merida would spend her days practicing archery and swordfighting, riding her horse, and exploring the Highlands. See them in Brave.
Matilda Wormwood is so smart, she taught herself how to be psychic. See them in Matilda.
A cruel pirate, Captain Hook still fancies himself a gentleman. See them in Peter Pan.