Because you like Liesl von Trapp in The Sound of Music

Aang is already a master airbender and once he learns to manipulate water, earth, and fire, he'll be truly unbeatable. See them in Avatar: The Last Airbender.

A benevolent madman with a blue box, The Doctor is traveling through time and space to heal the wounds of the universe. See them in Doctor Who.

It's hard to tell if Dean Winchester cares more about saving the world or his 1967 Chevy Impala. See them in Supernatural.

Joey Tribbiani's true passions in life are acting, sandwiches, football, sex, and asking ladies, "how you doing?" See them in Friends.

Percy Jackson is an ordinary student thrust into the world of myth come alive. See them in Percy Jackson & The Olympians: The Lightning Thief.

Gru's more misunderstood than evil, and if he'd rule over the world like he takes care of his three daughters, we'd be in good hands. See them in Despicable Me.

Dipper Pines is investigating a truly strange town during the world's wildest summer vacation. See them in Gravity Falls.

She's mostly doom and gloom, but you'd get nowhere without Sadness. See them in Inside Out.

Beca Mitchell fancies herself an edgy loner, but it turns out being part of a group can be aca-amazing. See them in Pitch Perfect.

Self proclaimed, Fat Amy, likes horizontal running and mermaid dancing. Important skills, one could argue. See them in Pitch Perfect.

Whether she's working as a mild-mannered assistant or an all-powerful superhero, Kara Danvers is defined above all by her huge heart. See them in Supergirl.

Finn is the world's last human who's "all about" understanding right and wrong. See them in Adventure Time.