Anya, Buffy the Vampire Slayer

After popping up in seasons three and four of Buffy, the rabbit-fearing Anya (Emma Caulfield) became a series regular in season five; her character shifted from demon to human to demon to human again, giving her lots of opportunities for fish-out-of-water humor—though she also fell in love, did plenty of self-exploration, and learned what it meant to be a true Scooby Gang member.