Because you like Leonard "Bones" McCoy in Star Trek

Jack Bauer is a terrorist fighter who is scared of nothing and no one. The clock is ticking! See them in 24.

Marv is a brutish but principled thug who'd be right at home on an ancient battlefield. See them in Sin City.

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.

Buttercup is a farm girl turned princess who'd do anything to have her old life back. See them in The Princess Bride.

Louise Belcher might be just a kid, but she can manipulate just about anyone with a pulse. All in the name of fun, of course. See them in Bob's Burgers.

Ellen Ripley defines the word "badass." When she's not leading her crew on an interstellar voyage, she's slaying terrifying creatures. See them in Alien.

With an abundant supply of alcohol, nice restaurants, and free will, Crowley is a demon who is thoroughly enjoying his time on Earth. See them in Good Omens: The Nice and Accurate Prophecies of Agnes Nutter, Witch.

Vincent Vega likes a good steak, a cheap milkshake, and killing a target without anything going wrong. See them in Pulp Fiction.

Barbara Kean is loving, selfless, and caring. But, she's less stable than she'd like to admit. See them in Gotham.

For Wreck It Ralph, it's not easy being the bad guy. Especially when you've been designed to destroy but really desire love. See them in Wreck-It Ralph.

Stranded on Mars, Mark Watney is armed with quick wits, an electronic diary, disco music, and an undying resolve to make it back. See them in The Martian.