Sperg is the local bully, who constantly bullies Billy, Irwin, Pud'n, and other kids to no end. He is a husky boy whose preferred method of terrorizing other kids is by administering his lethal wedgies. Despite his physical strength, he is frightened of Mandy because of her toughness and cynical attitude. On his shoulder, he has a heart tattoo that says "Mom". Sperg tends to be very emotionally sensitive, though he tends to keep this side of him under wraps. He has dreams of moving to New York City and having a career on Broadway when he grows up.