Because you like Bill Cipher in Gravity Falls

A kind, sensitive medical intern doing the best he can, George O'Malley sometimes struggles to keep up. See them in Grey's Anatomy.

A sadistic sociopath, Lil Z is helping make the City of God slum a Hell on Earth. See them in City of God.

If Lisbeth Salander can hurt a bastard who deserves it by digging up stuff about him, she feels good. See them in The Girl with the Dragon Tattoo.

Adults call him troubled and kids call him crazy, but Donnie Darko is too busy following the instructions of a giant bunny rabbit to care. See them in Donnie Darko.

Sydney Bristow is a kick-ass double agent on a mission for revenge. See them in Alias.

Helena is a mentally unstable, childish, and completely merciless. And most of all, she's an unstoppable killer. See them in Orphan Black.

Make sure not to anger the Hulk or else he will transform into a giant green monstrosity and smash anything in his way. See them in Marvel Cinematic Universe.

With each reboot, Janet progresses more and becomes capable of human emotions. See them in The Good Place.

Susanna Kaysen is an aspiring writer, despairing young woman who struggles with suicidal thoughts. See them in Girl, Interrupted.

Closing off her emotions makes Lightning a great fighter, but at what personal cost? See them in Final Fantasy Series.

Did he ever tell you the definition of insanity? Just wait, and this psychopath will do just that. See them in Far Cry 3.

Effy Stonem is cool and collected with a wry smile on her face and a cigarette between her lips. See them in Skins.