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The Wendigo (also Windigo, Weendigo, Windago, Windiga, Witiko, Wihtikow, and numerous other variants) is a mythical creature appearing in the mythology of the Algonquian people. It is a malevolent cannibalistic spirit into which humans could transform, or which could possess humans. Those who indulged in cannibalism were at particular risk, and the legend appears to have reinforced this practice as taboo.

Wendigo psychosis is a culture-bound disorder which involves an intense craving for human flesh and the fear that one will turn into a cannibal. This once occurred frequently among Algonquian Native cultures, though has declined with the Native American urbanization.

Wendigo psychosis is identified by Western psychologists as a culture-bound syndrome, though members of the aboriginal communities in which it existed believed cases literally involved individuals turning into Wendigos. Such individuals generally recognized these symptoms as meaning that they were turning into Wendigos, and often requested to be executed before they could harm others.