Some locals say they are eight feet tall and weigh 20 stone. Others claim they are even bigger, equipped with huge flesh-ripping teeth and muscles capable of dismembering a man.
Forest dwellers have told visiting explorers and scientists of a ferocious grey ape, with the cunning of a chimpanzee and the power and size of a gorilla - and a taste for meat rather than the shrubbery loved by most apes.
For, unlike most apes, these are predators - capable of hunting not only forest antelope but, incredibly, lion and leopard too. And to cap it all, like wolves, these fearsome beasts howl at the Moon.