Kids LOVE knock knock jokes, and this illustrated book by the New York Times-bestselling creators of the Happiness Is . . . project will leave them in stitches! The World's Best Knock Knock Jokes for Kids is filled with hundreds of corny, brilliant, and silly knock knock jokeseach paired with a small drawing that's a sweet comic gem in itself. It's the perfect book for road trips, rainy days, or those special moments when kids and parents can laugh together.