Gigantopithecus

Gigantopithecus are huge 12 feet gorillas that look like the smaller cousins of King Kong. Dwelling on the mountain slopes of Eodon in big clans, these gorillas are normally no threat at all, since they are vegetarians and not aggressive. However, there are always some of them that seem to run amok, and those are real dangerous. Animal and man alike flee when a Gigantopithecus grows truly mad.

Thankfully these mad individuals only seldomly appear.

Lore
''Family Pongidae. This primate is an enormous gorilla - like animal, standing some twelve feet in height and weighing in around 900 pounds, if my measurements of its tracks can be trusted. The native name for it translates roughly as the "black ghost" referring to the color of its hair and its solitary, normally shy habits. Though it does not seek out other animals - except for small rodents to supplement its otherwise vegetarian diet - it is a ferocious adversary when injured or angered, and the natives are terrified of it. Too, it is to be noted that there are occasional "rogue ghosts" who develop strange, deviant behavior, such as rampaging through the jungles and terrifying most men and animals in their path, or breaking away from their gigantopithecus clan and seeking to form new clans - often with smaller, intimidated "black ghosts" or even humans! In the Valley of Eodon, the Gigantopithecus dwells on the mountain slopes and ledges.''

-from "Ultimate Adventure Magazine", Savage Empire