The Amazing World of Gumball is one of my favorite cartoons. Every character on Gumball is some sort of nonhuman thing, like Teri, the paper doll girl at the far right. The first season used her for puns. Gumball (center) calls her personality “flat” in one episode. But the second season gave Teri a personality: She’s a hypochondriac. And it’s not because she’s made of paper. It’s because her mother is a doctor who has made poor Teri acutely aware that major illnesses start small.
I like that being a paper doll isn’t the cause of Teri’s personality, but a reflection of it. Everyone in Gumball’s class could be a real person, but what they are instead is a symbol for their true nature.