Gruagach
That is "long-haired one," from the Gaelic gruag, a wig: a fairy being with protective duties, to be met with in Scottish legends, and which apparently may be of either sex. The Gruagach appears to have been particularly associated with cattle, and milk was laid aside for him every evening - otherwise no milk would be got at next milking. Usually this being was of a beneficent nature, although occasionally it showed mischievous traits by loosing the cattle in the byres so that the herds had to get up, sometimes several times during a night, to tie them up: this apparently caused the Gruagach much delight. There are many tales in different parts of Scotland about the Gruagach, from which one gathers that this fairy commonly had long hair and was well dressed, of whichever sex it might happen to be. (See Scotland). a