Because you like Grunkle Stan in Gravity Falls
Megamind is searching for purpose in a supervillain life without a superhero to fight. See them in Megamind.
Princess Bubblegum is brilliant and determined, but can display a nasty temper. See them in Adventure Time.
Thanos is an intergalactic warlord, on the hunt for infinite power. See them in Marvel Cinematic Universe.
Jack Skellington is a nightmare-man with a soft heart and smooth voice. See them in The Nightmare Before Christmas.
Danny Zuko's car is auto-matic. Its system-matic. Its hyyyyydro-matic. Why, its greased lightning! See them in Grease.
Talos is a mysterious military commander skilled in the art of deception. 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.
Rick Sanchez is a gruff, alcoholic mad scientist, with the emphasis on "mad." See them in Rick and Morty.
Disgust is a friend who makes sure you stay away from all things gross. See them in Inside Out.
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.
A monstrous pirate captain, Davy Jones is quite literally heartless. See them in Pirates of the Caribbean: the Curse of the Black Pearl.