When summer starts in South Park, the boys decide to buy some fireworks to play with, which is a tradition between them that they do every summer. The boys decide to go to Stu's Firework Shack, however, Stu refuses to sell them any fireworks due to fireworks being outlawed in Colorado after a boy in North Park blew his hands off. He says that he can still sell the boys some black snakes, but they groan in disappointment.
Stu has combed dark brown hair and brown eyebrows. He wears a light blue button-up shirt with pockets on both sides, brown pants, and black shoes. He is overweight and seems to speak with a very slight lisp.
- He bears a great resemblance to Dr. Doctor. It is possible that the animators used the same model to create Stu.