Mannish Boy is a highly intelligent baby Stand user appearing in the 'Stardust Crusaders' arc of JoJo's Bizarre Adventure. Despite his infant appearance, he possesses a cunning and malevolent personality. His Stand, Death 13, has the ability to attack people in their dreams, trapping them in a nightmare world where he is omnipotent. Mannish Boy poses a significant threat to the protagonists as they journey to defeat DIO, using his abilities to create deadly illusions and manipulate reality within the dream world. His character highlights the bizarre and unpredictable nature of the JoJo universe.