The answer to the crossword for the term 'Creator of Boo Radley' is LEE, with three letters. Harper LEE was an American novelist who wrote the Pulitzer Prize-winning novel 'To Kill a Mockingbird' in 1960. The character of Boo Radley is a mysterious figure in the novel who is eventually revealed to be a kind and gentle person. Harper LEE's work has been widely praised for its exploration of racial injustice in the American South.