Because you like Jack Harkness in Doctor Who

R2-D2 has been in the galaxy saving business for decades. Not bad for somebody whose vocabulary is limited to "beep-boop." See them in Star Wars Series.

A meek schoolteacher, Mary Margaret Blanchard can't remember her past as a spirited, swashbuckling Snow White. See them in Once Upon a Time.

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.

With her mastery of martial arts and her prodigious building skills, Wyldstyle projects an air of invincibility. But she's not bulletproof. See them in The Lego Movie.

Turanga Leela is the daughter of two mutants who live in the sewers below New York City. See them in Futurama.

Jillian Holtzmann's madcap mind is always whirring and she will transform anything into one of her machines. See them in Ghostbusters (2016).

Leonardo is spiritual, and devoted to more than just pizza. See them in Teenage Mutant Ninja Turtles.

Manipulative, conniving, and ruthless, Mr. Gold is enigmatic no matter what world he's in. See them in Once Upon a Time.

A legendary warrior with a complicated relationship to the truth, Jaime Lannister is revered and reviled in equal measure See them in Game of Thrones.

The only constant in Night Vale is Cecil's hypnotic voice. See them in Welcome to Night Vale.

How is angel Aziraphale supposed to stop the apocalypse when Hell's forces misplaced the Antichrist somewhere? See them in Good Omens: The Nice and Accurate Prophecies of Agnes Nutter, Witch.