Because you like Alex Russo in Wizards of Waverly Place
Mystique is a shape-shifting mutant who, after too many disappointments, does not want to co-exist with humans. See them in X-Men Series.
If Jack Torrance is one of his moods, you'll be the unlucky victim of the most bone-chilling, sinister yellers around. Bring your own axe. See them in The Shining.
Buttercup is a farm girl turned princess who'd do anything to have her old life back. See them in The Princess Bride.
Newt Scamander is more comfortable with animals than people, even if the animals are super-dangerous magical creatures. See them in Fantastic Beasts and Where To Find Them.
A kind and funny valedictorian, Gwen Stacy likes to make out with Spider-man when her homework's done. See them in Marvel Cinematic Universe.
Louis de Pointe du Lac is wanting to find a way of living that doesn't make him miserable. See them in Interview with the Vampire: The Vampire Chronicles.
Just call Jeff Lebowski The Dude. Or His Dudeness, Duder, or El Duderino if you're not into that whole brevity thing. See them in The Big Lebowski.
Ash Williams is a houseware clerk at S-Mart and the Chosen One. See them in The Evil Dead.
Merlin is half awkward teenager, half super-powerful wizard. He serves Prince Arthur of Camelot during the day and illegally learns magic at night. See them in Merlin.