While in college, Jack and an illustrator friend, Nicole Ruben, began working on picture books. After a series of well-deserved rejections they published their first book, Rotten Ralph, in 1976. Jack continued to write children’s books and began to teach courses in children’s book writing and children’s literature.
Jack is the author of the Rotten Ralph books, which have been televised by the BBC. His novels Joey Pigza Swallowed The Key and Joey Pigza Loses Control are published by Corgi.