Two clips of Werewolf Transformation from the films The Company of Wolves (1984) & An American Werewolf in London

A werewolf, also known as a lycanthrope (from the Greek λυκάνθρωπος: λύκος, lukos, "wolf", and άνθρωπος, anthrōpos, man), is a mythological or folkloric human with the ability to shapeshift into a wolf or an anthropomorphic wolf-like creature, either purposely, by being bitten by another werewolf, or after being placed under a curse. This transformation is often associated with the appearance of the full moon, as popularly noted by 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 television shows cementing the werewolf's stance as a
dominant figure in horror.