"The Hat" is a popular children's book written by Jon Agee. It tells the story of a young boy who finds a hat that magically grows larger and larger. As the hat expands, it attracts various animals, each trying to fit inside it, leading to humorous situations. The story is known for its simple yet engaging illustrations and playful narrative. It encourages creativity and imagination, making it a favorite among young readers. "The Hat" is often used in classrooms to teach themes of sharing and friendship, as well as to inspire discussions about problem-solving.