Griffin

A griffin (also griffon or gryphon) is a creature with the body of a lion and the head and often wings of an eagle. They are resistant to most weapons and can only be killed using a magical enchantment. One particular griffin attacked Camelot during the reign of Uther Pendragon, who sent his son and a battalion of knights to attempt to kill it. They failed, but the griffin was later killed when Lancelot charged at it with a lance imbued with magic by Merlin.

Prior to this attack, the griffin was believed to exist only in myth. Information on griffins was obtained by Camelot's court physician Gaius in the castle library. (Lancelot)

The griffin is similar to a more vicious hippogriff in the Harry Potterverse.