Mannish Boy

Mannish Boy (マニッシュ・ボーイ) is a minor antagonist featured in Part III: Stardust Crusaders.

Mannish Boy is a baby, evil genius and Stand user in Dio's service who victimizes Kakyoin.

Appearance
Mannish Boy is an ethnically Indian baby. He has large ears and sharp canines, and wears a headscarf.

Personality
Mannish Boy is an impossible genius; able, though a baby, to think like an adult. He is able to defend himself from a scorpion, and even is seen smoking. When close to people, he tends to act like a normal baby, in order to avoid attention.

He only shows his true personality when his victims fall asleep close to him; allowing him to use his Stand, Death Thirteen. Through the Stand, disturbingly, Mannish Boy speaks easily, swearing and mocking; while still acting childish. He is also rather sadistic in killing his targets, prone to fits of maniacal laughter (written as a childish "hehehe") and boasting, though his overconfidence can betray him.

Mannish Boy may be one of the most sadistic and disturbing characters in the series, showing no respect for human life, and enjoying torturing its victims instead of killing them outright, despite being only a baby.

Abilities
Mannish Boy's Stand is Death Thirteen; able to exert lethal effects on his targets in dreams.

Demonstrating physical skill also unusual for his age, he kills a scorpion with a safety pin.

Stardust Crusaders
Mannish Boy was a baby that was given to the Joestar group by a woman, claiming that they needed to find his parents or he will be alone in the world. They agree, without knowing the woman was actually scared of him and that the baby was a Stand user.

Onboard an airplane, Mannish Boy uses his Stand to continuously attack Noriaki Kakyoin in his dreams, attacking the others when they also fell asleep. Kakyoin's violent movements in his sleep in response to the attack ended up downing the plane. As no one remembers what happened once awaken, everyone deemed Kakyoin crazy when he began suspecting the baby to be a Stand user.

He eventually found a way to remember the dream by writing a message in his own arm while dreaming. After his Stand is defeated and taken control of by Kakyoin, Mannish Boy is told that they are going to leave him in a nearby city where his mother should be around, from there he should return to his parents and stop mocking adults.

Kakyoin teaches him that lesson forcefully by mixing some of his excrement into his baby food. Naturally, Joseph and Polnareff, who are clueless about this and believe Mannish Boy to be hungry, decide to feed him the contaminated food, forcing Mannish Boy to learn his lesson, while Kakyoin acts like nothing had happened.

JoJo RPG (SNES)
The events from Death 13 occours in a different way. Unlike the storyline, in game Mannish Boy attacks the group from inside a plane en route to India.

Heritage for the Future (PS1/DC)
Mannish Boy appears only in Story Mode cutscenes; placed before and after Kakyoin's fight with Death 13.

JoJo's Bizarre Adventure: Eyes of Heaven (PS4/PS3)
Death 13's Nightmare Dream world where the Joestar Group was trapped, is a playable stage in the game. There is a stage gimmick where Death 13 will hunt your character down.

Trivia

 * For some reason, Mannish Boy possesses fangs similar to those of a Vampire.
 * Mannish Boy is one of only three infant Stand users in the series, joined by The Green Baby and Shizuka Joestar.
 * Although Mannish Boy only appears in the PS1 version of JoJo's Bizarre Adventure: Heritage for the Future, his Stand, Death Thirteen, appears in all versions as an NPC that can only be fought by the protagonists when certain conditions are met.