In Norse mythology, a vargr is a wolf, especially the wolf Fenrir and the wolves that chase the sun and moon Sköll and Hati. Based on this, J. R. R. Tolkien in his fiction used the form warg, which may incorporate Old English wearh, as the name of a particularly large and evil kind of wolf that could be ridden by orcs. Through Tolkien's influence, the concept has been used in fantasy works by other authors and in other media.
