Bestselling author Geoffrey Hayes has written and illustrated over forty children's books, including the extremely popular series of early readers Otto and Uncle Tooth, the classic Bear by Himself, the Patrick Bear books, and When the Wind Blew by Caldecott Medal-winning author Margaret Wise Brown.

His TOON Book series of Benny and Penny books has garnered multiple awards. In 2009, Benny and Penny in the Big No-No! received the Theodor Seuss Geisel Award given by the American Library Association for "the most distinguished American book for beginning readers published in English."