This is a one-of-a-kind illustrated knock knock jokes book, by the #1 children's books bestselling author and illustrator of "Tongue Twisters for Kids." Each Knock Knock joke features two illustrations; one as if you are looking through a peep hole on a door with someone (or something) knocking, and the other illustration featuring the punch line. Kids will find this book hilarious with the unique colorful cartoony illustrations and the silly knock knock jokes. Find out 'Who's there' behind each door, in this book of humor that features over 50 silly illustrated pages filled with funny knock knock jokes for kids.