Their origin is shown in the comic book that came with Action 52. They were created when they were cubs by the evil geneticist Dr. Morbiss when he killed their mother and took them for genetic research and turned them into half human, half cheetah creatures. They learn of Dr. Morbiss's plans and turn on him and escape, ultimately becoming his greatest enemy.
Named after the Greek hero, Hercules is the tallest and strongest of the Cheetahmen. He is a pacifist by nature but will fight when necessary. Because of his strength, he uses his bare hands for combat.
Named for the astrological sign, Aries is a combat expert who learns martial arts from movies shown to him by Dr. Morbiss. He fights using two clubs.
Named for the Greek God of the Sun, Apollo is the leader of the Cheetahmen and fights with a crossbow.