The Cheetahmen is a franchise created by Active Enterprises. It debuted in 1991 on the Nintendo Entertainment System multi-cart Action 52. There was also an extremely rare sequel and a Sega Genesis version.
Mad scientist Dr. Morbis kills a mother cheetah while on safari in Africa, then takes her three cubs for his genetic research. Subjected to his experiments, the cubs grow into half-cheetah, half-human creatures. Once they learn of Morbis' evil plans, they turn on him, and he, in turn, creates an army of half-animal humans (known as "Sub-Humans") to stop the Cheetahmen once and for all.
The NES version of the game had an intro sequence that told a story as well, where a boy called the "Action Gamemaster" is at home playing a video game when a robotic arm reaches through the screen and pulls him into the game by his leg. He meets the Cheetahmen, who then run away. The Gamemaster does not appear in the rest of the game, although the manual summary implies that he transforms into the Cheetahmen, one after another. There is no mention of Dr. Morbis in this version of the game, but there are villains from the comic book present in the game. Cheetahmen is also known as Action Gamemaster because of the title screen, but it can't be because of his importance because he is never mentioned again.