The Garden has the Giggles in this funny joke book about vegetables Knock, Knock. Who's There? Lettuce. Lettuce Who? Lettuce In and you'll find out! In this funny collection of illustrated jokes from Brenda Ponnay, little ones will laugh at their favorite vegetables. Don't miss the other Illustrated Jokes books from Brenda Ponnay: Knock Knock, Boo Who? Knock Knock, Moo Who? It's Snot Fair!