Because you like Liesl von Trapp in The Sound of Music
Steven Universe is an excitable youth who likes junk food and trying to save the world. See them in Steven Universe.
John Watson is haunted by his past (who isn't) but he's starting to branch out with some help from a world class detective. See them in Sherlock.
Edward Elric has a quick mind along with a quick temper. See them in Fullmetal Alchemist.
Unaware of the fact that he's a toy and made of plastic, Buzz Lightyear is a spaceman on a mission fully of snappy catch phrases. See them in Toy Story.
A caring, curious, and considerate android, Vision could crush your skull if he had to. But he'd rather not. See them in Marvel Cinematic Universe.
Dory is more than a little forgetful, but she'll always remember to have your back. See them in Finding Nemo.
Emmet Brickowski is so upbeat it's not even human. Everything is AWESOME! See them in The Lego Movie.
Castiel might be an immortal angel, but the human world is still more than a little confusing. See them in Supernatural.
There's never a dull moment when this mischievous high-schooler gets up to his hijinks. Save Ferris! See them in Ferris Bueller's Day Off.
Hiccup Haddock III may be the only Viking nerd in recorded history. See them in How to Train Your Dragon.
Brilliant, violent, and only a little insane, the Joker doesn't listen to anyone except the voices in his head. See them in DC Extended Universe.
Armed guards, FBI agents, notorious serial killers – Hannibal Lecter has bested them all, with time to finish dessert afterwards. See them in The Silence of the Lambs.