Because you like Lexie Grey in Grey's Anatomy

Donatello might come off as a tad nerdy, but don't let his geekiness fool you. He's a trained ninja and a skilled fighter. See them in Teenage Mutant Ninja Turtles.

For the sake of science, Kurisu Makise will persevere no matter how deep into the dark secrets of the world she finds herself. See them in Steins;Gate.

A malevolent dark wizard, Voldemort is so fearsome that he's known primarily as "He Who Must Not Be Named." See them in Harry Potter Series.

A determined and cold-hearted spy, Cassian Andor will do what it takes to stand up to the evil Galatic Empire. See them in Rogue One.

Jane Smith is a stone-cold killer, but you would never know it from looking at her. See them in Mr. & Mrs. Smith.

Holly Golightly spends so much time trying to be other people's dream girl, she doesn't really know what kind of girl she actually is. See them in Breakfast at Tiffany's.

Bella Swan thinks of it as her job to help her parents and protect her friends, even though it often ends up the other way around. See them in Twilight.

Jack's big imagination is never limited by his incredibly cramped surroundings. See them in Room.

K-2SO is a blunt and sarcastic reprogrammed Imperial droid who is always up for an adventure. See them in Rogue One.

Shaggy might be a bit of a slacker, but his heart and his stomach are usually in the right place. See them in Scooby-Doo.

Driven by obsession and anxiety, Monk bravely overcomes, or at least battles, his fears to help the world. See them in Monk.

Gloria Delgado-Pritchett's big personality is rivaled only by her big heart. Wait, did we mention she's gorgeous? See them in Modern Family.