All monsters begin as something mundane. The fractal begins with simple rules, and then spirals out into something more, and sometimes, something much worse. The origins of the Giants are unknown to the Psychonauts, but the origins of the Wendigo are not. The Wendigo were once human.
The Wendigo are what happens when the hunger of the Grey Locust is left wild and uncontained by the Locust King and the constraints that the Grey places upon the Hungry Empire in an attempt to maintain its cold order.
The hunger drives them, and in the early stages they still seem human.
The Stillborn
From a distance, one might mistake the Stillborn for people. Up close, the mistake is unlikely. The Stillborn's skill has gone white and chalky, and clouds of dry skin cells explode around them with sudden movements. Their eyes have gone milky blue-white and the skin has tightened all across the face to give the eyes a sunken look. The Stillborn's hair has bleached to translucent silver and seems to defy gravity, floating about the skull like an unholy halo.
The Stillborn still speak, but their language is unintelligible to any non-wendigo. They have their own culture and mythology, those none who understand it are able to transmit it back to those who still understand human speech. The path to hunger is nearly always a one way journey.
The Hungry Ghost
As the body is consumed by the hunger, the Stillborn go from emaciated to truly skeletal, with skin stretched so tightly of bone and sinew that they could be mistaken for desiccated corpses if they choose to remain still. The teeth sharpen and elongate and the eyes decompose completely in the head, replaced by cold blue lights. At this point, the Wendigo is known as a Hungry Ghost. The Hungry Ghost, like the Stillborn army, still physically eat. However, they no longer attempt to cook their food, and seem unable to digest it- as the food sits inside their huge distended bellies.
The Ravener
The final state of deterioration. The Wendigo's head is now a skull with glowing eyes, resembling nothing so much as the terrible love child of an elk and a bear. Carnivores teeth poke out of a herbivore's jaw. A predator's eyes sit uneasy in the skull of a prey animal. What skin remains is ragged and wispy and flutters in the slightest breeze. The Ravener is an animate skeleton that glows with a cold blue light. The body of the skeleton too is twisted, elongated and ape-like, but with the hooves of an ungulate, the ribcage and fore paws of a polar bear, and bizarre protrusions extending from the individual vertebra of the spinal column.