What are Stanley's character traits?

Stanley Yelnats is the main character of Holes by Louis Sachar. He is a fourteen-year-old boy with a good heart but a history of bad luck, which runs in his family. This bad luck is to blame for his being accused of a crime he did not commit and sent away to Camp Green Lake.
Physically, Stanley is described as overweight—a trait which earns him the nickname "Caveman" at camp. Over the course of the novel, due to the grueling work of digging holes and the emotional trauma of surviving Camp Green Lake, Stanley loses weight and toughens up, learning to stand up for himself. Ultimately, he breaks his family's curse, ending his streak of bad luck with a stroke of good fortune.