Size and Weight:
The literal 1,000-pound gorilla sitting in the corner of a natural history museum, the appropriately named Gigantopithecus was the largest ape that ever lived, not quite King Kong-sized but much bigger than the modern lowland gorilla. Or, at least, that's the way this prehistoric primate has been reconstructed; frustratingly, practically everything we know about Gigantopithecus derives from its scattered, fossilized teeth and jaws, which first came to attention when they were sold in Chinese apothecary shops in the first half of the 20th century. Paleontologists aren't even sure how this colossus moved; the consensus is that it must have been a ponderous knuckle-walker, like modern gorillas, but a minority opinion holds that Gigantopithecus may have been capable of walking on two feet.
Another mysterious thing about Gigantopithecus is when, exactly, it lived. Most experts date this ape to mid-Pleistocene eastern and southeastern Asia, about one million years B.C., and it may have survived in small populations until as late as 200,000 or 300,000 years ago. However, a small community of cryptozoologists insists that Gigantopithecus never went extinct, and persists today high up in the Himalayan Mountains as the mythical Yeti, better known in the west as the Abominable Snowman! (As fearsome as it looked, though, Gigantopithecus seems to have been mostly herbivorous, subsisting on fruits, nuts, bamboo shoots and only the occasional small, quivering mammal or lizard.)