Because you like Sheldon J. Plankton in SpongeBob SquarePants

A suave demon, Crowley grants humans their wishes in exchange for their soul, only to find loopholes that benefit him. See them in Supernatural.

A vampire hunter, Integra Hellsing doesn't tolerate failure, least of all her own. See them in Hellsing.

Gregor Samsa is an ordinary man in an abnormal predicament. See them in The Metamorphosis.

Amy Santiago likes following the rules a little too much. See them in Brooklyn Nine-Nine.

With most of the people that Sango loved now gone, the only thing she wants is to kill the demon who destroyed her village. See them in Inuyasha.

Chris Miles has run out of cash, luck, and drugs. See them in Skins.

Hotheaded and arrogant, Kaneda is nevertheless fiercely protective of the biker gang he leads. See them in Akira.

Sid Jenkins is the ultimate underachiever, but he doesn't mind. Well, he pretends he doesn't. See them in Skins.

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

Terence Fletcher is a brutal and unflinchingly strict music teacher hell-bent on whipping his students into shape. See them in Whiplash.

Jeff Winger thinks he's too cool for school, which is a problem because he just enrolled in community college. See them in Community.

Andy Dwyer might not be completely literate, but he makes up for it in spirit. See them in Parks and Recreation.