A horse may be able to jump over the moon. Can a cow do it? Hey Diddle Diddle. The hook books are for very small readers, aged five and above (for being read to) and six and above (for reading independently). written by some of the best-known writers for children, and illustrated in exuberant colour by some of India's most-loved illustrators. Hawaldar hook is the endearing mascot of the hook books.