The ubyr is the devourer of Tatar belief, its very name derived from a Turkic verb 'to swallow'. It takes two connected forms: the ubyrly karchyk, a living old witch whose soul is said to leave her sleeping body by night and fly abroad as a ball of fire to feed on the living, and the malignant dead — a corpse that will not rest but rises to consume flesh and life. Insatiable hunger defines the creature in every telling. The word carries a wider fame than the figure: Tatar and kindred Turkic ubyr is generally held to be the source of the Slavic upyr, and through it of the international term 'vampire', so that the roots of one of the world's best-known monsters reach back into the folklore of the Volga.