Because you like Leonard "Bones" McCoy in Star Trek

A scary monster on the outside, James P. Sullivan is really a softie on the inside. See them in Monsters, Inc..

One of the best in the magical world, Mad-Eye has the battle scars to prove his dedication to such a dangerous job. See them in Harry Potter Series.

Felicity Smoak is a brilliant hacker who nonetheless becomes tongue-tied in front of attractive men. See them in DC Extended Universe.

Klaus Baudelaire's photographic memory saves the lives of his siblings many times over. See them in Lemony Snicket's A Series of Unfortunate Events.

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

Christine Daae has been secretely taking lessons from a phantom musician. It sounded less creepy in her head. See them in The Phantom of the Opera.

A singing nanny, Mary Poppins is practically perfect in every way. See them in Mary Poppins.

Donna is boisterous and spunky traveller of the TARDIS, exploring worlds beyond the simple mundane enterprises of Earth. See them in Doctor Who.

Arwen has to choose between a life of loneliness or love and inevitible death, both rather unfortunate options. See them in The Lord of the Rings.

Kesuke Miyagi is a karate expert who thinks the best way a scrawny high schooler can learn how to defend himself is by washing every surface in sight. See them in The Karate Kid.

Faith has a chip on her shoulder and a stake in her hand to slay vampires in her town. See them in Buffy the Vampire Slayer.

This mathematical genius doesn't have time for small talk; Alan Turing needs to break Enigma, the Nazi's cipher machine. See them in The Imitation Game.