A friend of Andy's. She is a smart-mouthed, skeptical girl. Despite an age difference, she often serves as the perfect foil for Mouth, as the two butt heads constantly (which later translates into a form of flirtation). Although just as jumpy as Andy during their adventure, Stef is far more organized in thought. Although she comes across as something of a smart-alec, she demonstrates that she can be quite compassionate.