CHRIS GRABENSTEIN made his picture-book debut with No More Naps! and is the #1 New York Times bestselling author of the Mr. Lemoncello's Library, Dog Squad, Smartest Kid in the Universe, and Welcome to Wonderland series. He's also the author of The Island of Dr. Libris; Shine!, coauthored with J.J. Grabenstein; and many other books. Chris lives in New York City with his wife, J.J., and their cats, Luigi and Phoebe Squeak.

Leo Espinosa is a New York Times bestselling illustrator and designer from Bogotá, Colombia. His picture books include Islandborn (by Junot Díaz), for which he was awarded a Pura Belpré Illustrator Honor; No More Naps! (by Chris Grabenstein); and The World Belonged to Us (by Jacqueline Woodson). His work has been featured in a variety of publications, products, animated series, and gallery shows worldwide, and his award-winning illustrations have been recognized by American Illustration, Communication Arts, Pictoplasma, 3x3, and the Society of Illustrators (with Gold and Silver Medals). Leo also serves on the faculty of Rhode Island School of Design. He lives with his family in Salt Lake City.