Barnett is the author of several books for children, including "Extra Yarn,” illustrated by Jon Klassen, a Caldecott Honor Book and winner of a Boston Globe-Horn Book Award, and "Sam and Dave Dig a Hole,” a Caldecott Honor Book and winner of the E. B. White Read Aloud Award. He is the co-author of the New York Times best-selling series "The Terrible Two.” Barnett lives in California.