Here are some of his most popular books:
* The Paper Bag Princess (1983) - This feminist fairytale has become a classic.
* The Tale of the Three Princes (1992) - A funny retelling of a classic fairytale.
* The Librarian Who Measured the Earth (1995) - A story about a librarian who travels the world.
* The Story of Babar (2002) - A retelling of the classic elephant story.
He also wrote many other books for children, including picture books, chapter books, and novels. He is known for his witty and creative writing style, and his books are often enjoyed by children and adults alike.