This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Warg (English and Scandinavian)
A warg is a particularly large and evil kind of wolf that could be ridden by orcs. He derived the name and characteristics of his wargs by combining meanings and myths from Old Norse and Old English. In Norse mythology, a vargr (anglicised as warg) is a wolf, especially the wolf Fenrir that destroyed the god Odin in the battle of Ragnarok, and the wolves Skoll and Hati, Fenrir's children, who perpetually chase the Sun and Moon.
There are also lesser wargs that nonetheless overshadow the common wolf. Some of these lesser wargs serve as steeds for various jotnar and aesir. While more cunning than ordinary wolves, nothing indicates that a lesser warg shares the ability to speak with their greater brethren. However, they their actions indicate a high degree of intelligent malevolence.