From New York Times bestselling author Mac Barnett and Geisel Award-winning illustrator Greg Pizzoli, an uproarious early reader series about a mischievous rabbit, a cranky old lady, and a lovable dog. The Lady gives Jack a gift. It's a lab kit Jack goes into the shed to experiment and doesn't come out until he's made another Jack and another Jack and another. But one Jack was already too many. Can Jack stop his naughty robot clones before they destroy...