Wendigo

Wendigo (/ˈwɛndɪɡoʊ/) is a mythological creature or evil spirit which originates from the folklore of First Nations based in and around the East Coast forests of Canada, the Great Plains region of the United States, and the Great Lakes region of the United States and Canada, grouped in modern ethnology as speakers of Algonquian-family languages. The wendigo is often said to be a malevolent spirit, sometimes depicted as a creature with human-like characteristics, which possesses human beings. The wendigo is known to invoke feelings of insatiable greed/hunger, the desire to cannibalize other humans, as well as the propensity to commit murder in those that fall under its influence. Humans overpowered by greed could turn into wendigos. Wendigos were created when a human resorted to cannibalism to survive. Humans could also turn into wendigos by being in contact with them for too long.
In Ojibwe, Eastern Cree, Westmain Swampy Cree, Naskapi, and Innu lore, wendigos are often described as giants that are many times larger than human beings, a characteristic absent from myths in other Algonquian cultures. Whenever a wendigo ate another person, it would grow in proportion to the meal it had just eaten, so it could never be full. Therefore, wendigos are portrayed as simultaneously gluttonous and extremely thin due to starvation. The wendigo is seen as the embodiment of gluttony, greed, and excess: never satisfied after killing and consuming one person, they are constantly searching for new victims. A wendigo need not lose the human's powers of cognition or speech and in some depictions may clearly communicate with its prospective victims or even threaten or taunt them.
The Wendigo was gaunt to the point of emaciation, its desiccated skin pulled tightly over its bones. With its bones pushing out against its skin, its complexion the ash-gray of death, and its eyes pushed back deep into their sockets, the Wendigo looked like a gaunt skeleton recently disinterred from the grave. What lips it had were tattered and bloody ... Unclean and suffering from suppuration of the flesh, the Wendigo gave off a strange and eerie odor of decay and decomposition, of death and corruption.