To Kill a Mockingbird is a novel by Harper Lee published in 1960. The mockingbird only sings to please others and therefore it is considered a sin to shoot a mockingbird. They are considered harmless creatures who give joy with their song. The mockingbird image or symbol appears four times in the novel. Two characters in the novel symbolize the mockingbird: Tom Robinson & Boo Radley. It was immediately successful, winning the Pulitzer Prize, and has become a classic of modern American literature.