Billy is a shy man whose special demon is fear. Because his mother and Nurse Ratched are friends, and because Billy is a “little mummy’s boy”, the Nurse has a special power over him. Billy wants to please everybody, but he also wants to be his own man. These two opposing forces render him helpless until McMurphy comes along. McMurphy encourages Billy’s interest in the opposite sex and arranges for Candy to visit Billy. But when Nurse Ratched confronts Billy, she’s able to bring him right back to the place of shame and fear that he’s always occupied. He is so ashamed, in fact, that he commits suicide. His suicide serves as the event that propels McMurphy’s final confrontation with Nurse Ratched.
William "Billy" Bibbit in the Essays