From Mo Willems, the multi award-winning, New York Times bestselling creator of the Pigeon series and the Knuffle Bunny trilogy, comes a companion title to Leonardo, the Terrible Monster. One day, Sam, the most scaredy-cat kid in the whole world, makes a terrifying discovery. It's not Frankenthaler the monster. It's her friend Kerry! Kerry, the second most scaredy-cat kid in the whole world, also makes a terrifying discovery. It's not Leonardo the monster. It's his friend Sam! "AAAAH!" yells Sam. "EEEEK!" yells Kerry. Something has to be done. Something BIG. But what?