A werewolf, also known as a lycanthrope, is a mythological or folkloric human with the ability to shapeshift into a wolf, often after being placed under a curse and/or lycanthropic affliction via a bite or scratch from a werewolf. This transformation is often associated with the appearance of the full moon.
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 or after being placed under a curse and/or lycanthropic affliction via a bite or scratch from a werewolf, or some other means. 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, speed, 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 fiction, although fictional werewolves have been attributed traits distinct from those of original folklore. For example, the ideas that werewolves are only vulnerable to silver bullets or that they can cause others to become werewolves by biting or wounding them derive from works of modern fiction. 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.
In medieval Europe, the corpses of some people executed as werewolves were cremated rather than buried in order to prevent them from being resurrected as a vampire. Before the end of the 19th century, the Greeks believed that the corpses of werewolves, if not destroyed, would return to life as vampires in the form of wolves or hyenas which prowled battlefields, drinking the blood of dying soldiers. In modern fiction, werewolves and vampires are often portrayed as antagonists, with many works — including most notably the Twilight series — portraying the two races as ancient enemies.
Source: Werewolf on the English Wikipedia