"Harold and the Purple Crayon" is a children's book written by Crockett Johnson. It tells the story of a young boy named Harold who uses a purple crayon to create his own world. With his imagination, he draws various objects and landscapes, leading him on whimsical adventures. As Harold explores his creations, he encounters challenges and learns to solve problems using his creativity. The book emphasizes the power of imagination and the idea that one can shape their own reality through art and creativity. It has become a classic in children's literature since its publication in 1955.