Because you like Callie Torres in Grey's Anatomy
Trevor Phillips is an unpredictable maniac who tortures people for no reason. See them in Grand Theft Series.
Aldo Raine is in the killing Nazi business. And as he says, business is a-boomin'. See them in Inglourious Basterds.
Chaos is what killed the dinosaurs, and there's nothing Jason "J.D." Dean loves more than chaos. See them in Heathers.
Emily Fields has been very guarded, careful of whom she trusts and reveals her secrets to. See them in Pretty Little Liars.
Give in to the dark side with vampire Lestat; it's more fun. See them in Interview with the Vampire: The Vampire Chronicles.
Point the fun-loving Pippin Took towards second breakfast, and he's one happy hobbit. See them in The Lord of the Rings.
Satine cynically gives up on love so she can advance her singing career. But she meets a dreamer who reminds her there's more to life than ambition. See them in Moulin Rouge.
Burton Guster is a level-headed investigator with a "Super Sniffer" nose. See them in Psych.
Nadine Franklin likes to wallow in her misery almost as much as she likes to torment her mother. See them in The Edge of Seventeen.
Roger is a pansexual alcoholic non-human who will happily lie, cheat and steal to get what he wants. See them in American Dad!.
Billy Butcher's job is to give everyone hell by any means necessary. See them in The Boys.