Marceline McAllister - Misfit girl at school. Plays the trombone. Kind of tall and gawky. Rides a bike, in the end hits a cow. She knocks Jason over in a snowball fight and shoves snow in his face. Hates McDonald's. Can run the mile faster than Jason, which irks him, however, he beats her in the final mile race at the end of the book. Jason gets suspended for skipping out on Marceline's trombone performance and is forced to apologize to her. Since then, Jason could not stand her and complains every time that he has contact with her. But at the end of the book, she and Jason become sweethearts.