Because you like Donna Noble in Doctor Who

Alex Danvers is a brilliant engineer tasked with alien threats, and one of those aliens is her adopted sister Supergirl. See them in Supergirl.

Lily Aldrin is a flaky but supportive kindergarten teacher and painter. See them in How I Met Your Mother.

Marlin navigates through shark-infested waters, angry anglerfish, a jellyfish bloom and hungry whales to search for his son. See them in Finding Nemo.

Haymitch Abernathy is a trainer for the tributes of District 12, although he's never sober enough to give much advice. See them in The Hunger Games .

What Troy Barnes lacks in common sense, he makes up for with heart. See them in Community.

Edmund Pevensie isn't a bad person, but he did sell his siblings out for a tin of Turkish Delight. See them in The Chronicles of Narnia.

Garnet is a Crystal Gem who'll protect her friends with her life. See them in Steven Universe.

A loyal assistant to Nelson and Murdock, Karen Page has a way of finding trouble. See them in Marvel Cinematic Universe.

A brave but pessimistic nobleman, Boromir knows one does not simply walk into Mordor. See them in The Lord of the Rings.

Michael Kelso gets by on his good looks and his openhearted nature. See them in That '70s Show.

A no-nonsense professor famous for her strictness, Minerva McGonagall only shows her warmer side to those closest to her. See them in Harry Potter Series.

Green skin, pointy hat, evil cackle—this villain has it all! See them in The Wizard of Oz.