This book is about a boy named Sammy. One day he sees a Sofa Monster, who is helpful because it ate Sammy's peas, and Sammy doesn't like peas. After dinner they meet up under Sammy's bed and make a deal. The deal is if the sofa monster eats Sammy's vegetables everyday, he will give the monster gum. The sofa monster wants gum because he found gum under the sofa and he wants more for his family and friends.