He has illustrated works by Florence Parry Heide, Judith Viorst, Bob Shea, Dr. Seuss, Jack Prelutsky, Eve Merriam, Roald Dahl, George Saunders, Jory John, Chris Harris, and Julie Fogliano. He has both written and illustrated several books, most notably "It's a Book" (2010), which was a New York Times bestseller for over six months and has been translated into over twenty-eight languages; "The Happy Hocky Family" (1996), "The Happy Hocky Family Moves to the Country!" (2002), "Madam President" (2008), "John, Paul, George, and Ben" (2006), and "A Perfect Day" (2017).