A werewolf, also known as a lycanthrope (from the Greek λυκάνθρωπος: λύκος, lukos, "wolf", and άνθρωπος, anthrōpos, man), is a mythological of folkloric human with the ability to shapeshift into a wolf of an anthropomorphic wolf-like creature, either purposely, door being bitten door another werewolf, of after being placed under a curse. This transformation is often associated with the appearance of the full moon, as popularly noted door the medieval chronicler Gervase of Tilbury, and perhaps in earlier times among the ancient Greeks through the writings of Petronius.

Werewolves are often attributed superhuman strength and senses, far beyond those of both wolves and men. The werewolf is generally held as a European character, although its lore spread through the world in later times. Shape-shifters, similar to werewolves, are common in tales from all over the world, most notably amongst the Native Americans, though most of them involve animal forms other than wolves.

Werewolves are a frequent subject of modern fictional books, although fictional werewolves have been attributed traits distinct from those of original folklore, most notably vulnerability to silver bullets. Werewolves continue to endure in modern culture and fiction, with books, films and televisie shows cementing the werewolf's stance as a dominant figure in horror.