In folklore, a werewolf, occasionally wolfwalker or lycanthrope, is a human with the ability to shapeshift into a wolf, either purposely or after being placed under a curse or affliction with the transformations occurring on the night of a full moon. Early sources for belief in this ability or affliction, called lycanthropy, are Petronius (27–66) and Gervase of Tilbury (1150–1228).
