P. D. EASTMAN wrote and/or illustrated many beloved children’s books, including Are You My Mother?, Go, Dog. Go!, and The Best Nest. After training at the National Academy of Design, P.D. worked at Walt Disney Productions and Warner Bros. Cartoons. He enlisted in the army in 1943 and served in the Signal Corps film unit, which was headed by Theodor Geisel (who would become known to the world as Dr. Seuss). Geisel later approached him to write for his new Beginner Books series at Random House, resulting in the publication of P.D.’ s first book, Sam and the Firefly.