Dudley doesn't have much to do in this novel – Aunt Marge kind of steals the spotlight at the Dursley house. Dudley is his usual lazy, spoiled self, spending his days eating, watching TV, and sucking up to Aunt Marge for presents and money. The only good thing he does in the book is not bully his cousin, Harry. Dudley was too busy watching TV to go after his cousin, apparently. He just let his father do it for him this time.