GWILLION, GWYLLION
Mythology of Wales
Evil Mountain Fairies
Takes the shape of a goat
These are the evil mountain FAIRIES in the folklore of Wales. The GWILLION are described as hideous HAGS seen walking on the roads in foul weather. They could also materialize in the shape of goats. It is said that they combed the goats’ beards on Wednesdays, the FAIRY Sabbath. The most feared of them is the OLD WOMAN OF THE MOUNTAIN. The GWILLION, when not leading night-bound travelers astray in the mountains and forest, may call at the homes of the community about Aberystwyth, where the terrified inhabitants allow the GWILLION to shelter on stormy nights. These supernatural HAGS, like many others of their kind, are vanquished and disappear at the sight of an iron knife.
Source: Spirits, Fairies, Leprechauns, and Goblins Encyclopedia