Because you like Spike in Buffy the Vampire Slayer

This high school queen bee has everything, including a genius-level IQ—a fact Lydia Martin keeps hidden to maintain her image. See them in Teen Wolf.

When the going gets tough, Rick Grimes gets tougher. It's a very useful trait when the world goes to hell. See them in The Walking Dead.

In Ziva David's world, you grow up fast; you don't have a choice. See them in NCIS.

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.

Ishmael is a quiet observer on a larger-than-life quest. See them in Moby Dick.

Juno MacGuff is hoping sarcasm will get her through the stress of teenage life. And also, teenage pregnancy. See them in Juno.

Castiel might be an immortal angel, but the human world is still more than a little confusing. See them in Supernatural.

If there's any hope of resolving things peacefully, this proud ape leader will have to trust the humans. See them in Dawn of the Planet of the Apes.

Jenko was top dog in high school. Now he's bottom of the pack in the police academy. See them in 21 Jump Street.

Korra is stubborn, outgoing, and faced with huge responsibilities she might not be ready for. See them in The Legend of Korra.

A believer in the pursuit of justice, Garrus Vakarian hates it when bad guys slip through the cracks of the bureaucratic justice system. See them in Mass Effect.

If you need her, Lisa Simpson will be in her room with her saxophone and a good book. See them in The Simpsons.