Dr. Arthur Nagan was a former surgeon who took the organs from gorillas to use in people. However, his scheme was allegedly thwarted by the gorillas, who somehow transplanted his head onto a gorilla’s body[2]. He was the leader of the Headmen and a former member of the Lethal Legion. Among his "achievements" was transplanting the head of Chondu the mystic onto a variety of unsuitable bodies, including that of Nighthawk[3] as well as a monstrous body with tentacles and wings[4]. He also managed to shrink the Defenders, Nebulon as well as US President Gerald Ford to miniature size and trap them unde a glass bowl so he could study their behavior

Powers
Nagan possesses the body of a gorilla, which gives him the strength, agility, speed and reflexes of a gorilla.

Abilities
Nagan is a brilliant surgeon who can transplant almost any living living tissue or organ into another organism.
Strength level

Nagan can lift about two tons