The Wolf, The Duck, and The Mouse by Mac Barnett and illustrated by John Klassen is a whimsical picture book for children aged 2-5, published by Walker Books. This clever and humorous story follows a mouse and a duck who live happily inside the belly of a wolf, turning an unusual situation into an entertaining tale of friendship and adventure. The book's stunning illustrations and witty narrative make it a delightful read for both children and parents.