The Wendigo (also known as Windigo, Weendigo, Windago, Windiga, Witiko, Wihtikow, and numerous other alias variants including "Manaha") is a mythical monster from varied Native American cultures.
Wendigo who existed in areas where the winter caused it to become isolated due to heavy snow and adverse conditions: in these harsh conditions it was believed that the practice of cannibalism was occasionally practiced and the Wendigo was believed to be the result of such actions.
Often said to have been human, the Wendigo had become transformed via the act of cannibalism into an eternally hungry monster that had no real universal appearance: though a common depiction, introduced by one Blackwood in the eighteenth century, is simply of a heavily emaciated human figure, albeit badly decomposed and smelling of the grave; this version of the Wendigo was simply an emaciated human, who has been driven to insanity by the possessing spirit. Other versions included a deer-headed decomposing humanoid most likely deriving from the close relatives of Wendigo, the Skinwalkers; or a large hairy humanoid with a heart of ice, most likely confused from legends of the Yeti; the concept of the Wendigo was likely formed as a warning against cannibalism. Currently, Native Americans see any capitalist force as a "Wendigo" due to the destructive powers of such businesses which may have no respect for the land.
Fame
The Wendigo has become a popular monster in fiction and somewhat of a staple in horror/fantasy, like Sleepy Hollow and Supernatural, although depictions vary drastically from story to story (though the idea of a large, hairy humanoid is still the most common one) - although the Wendigo itself is almost entirely mythological science has named a cultural phenomena the "Wendigo Psychosis".
The SCP-323 anomaly seems to come from the Wendigo.
Wendigo Psychosis
This is a rare condition in which individuals start to crave human flesh even when other food is in supply and interactions with people suffering from this condition may also of contributed to the legend of the Wendigo. This mental illness is very similar to Cabin Fever and Isolationism, and sufferers often describe being influenced by an external malevolent force.
Wendigos in Fallout 76 are cannibalistic humans that have been mutated by nuclear radiation into horrifying beasts some can even mutated into the tall three headed colossus.