Fuath (plural fuathan, meaning “hate” in Scottish Gaelic) refers to a class of malevolent water spirits in Highland Gaelic mythology. These spirits are said to inhabit the sea, rivers, lakes, and sea lochs of Scotland and Ireland.
In Gaelic folklore, any being that frequently changes its shape is of evil origin. The case of the Fuath confirms such thinking. A Fuath can sometimes be seen, if it chooses to take on a physical appearance. Most fuathan have the power of transforming themselves in many things even angels of light. They use this power to trick their victims but they are generally found out in the long run. Most often, they present themselves as humanoid creatures, with green skin and the mane and tail of a yellow horse.
Fuaths have no noses, but they have very keen eyes, which they use to find humans when they dare to enter their watery homes. If angry, they will pull unsuspecting swimmers underwater to their deaths using their webbed hands and feet.
Fuathan are most resentful against those who damage or take advantage of their surroundings. It is believed among the people, that a curse follows the killing of fish in spawning time, and that those who are not careful of such taboos—such as careless sportsman who enjoys fishing at all times—are apt to encounter a fuath and feel its temper.
In fear of the fuath, many men would not dare to go to catch fish. An account of an encounter with an angered fuath was recorded by Goodrich-Freer in his work “The Powers of Evil in the Outer Hebrides” as follows:
“There was a man fishing, so entranced in the task, it took him time to perceive that another person was coming down the stream. It seem to be a man, and the fisherman told him to step aside so as not to frighten the fish, and the man obeyed. The fisherman had caught a good quantity of fish by this time, and following up the stream he was surprised to see something like a mill wheel rolling down towards him, in a way he did not think canny, and he deemed it prudent to decamp with all speed. He picked up his fish hurriedly and put them on a basket, with the exception of one, which he had decapitated accidentally by trampling on it with his boot. As he was going away, he stowed the fish in a nook where he could afterwards easily find them, and hurried off to the nearest dwelling. On his way over the moor, he was frequently thrown on the ground by some unseen power. On asking if it had any part with God, he got no answer. In the morning he returned for his fish and got none but the headless one.”
According to the record, the fisherman was informed of his fault and the fact that a fuath had caused his falling and had taking the fish.
It is significant to remember that fuathan are clever and difficult to get rid off. For example, it is not right to call dogs by name at night, for that will inform the fuath, and then he can call the dogs as well as you, and make them follow himself, letting you without protection against beast and thieves. So it is said that it’s best to leave them alone, rather than to try and trap them or destroy them.
One more thing, while both are aquatic creatures the fuath should not be mistaken with the kelpie—a close relative of the Nykur—for the kelpie is a flesh and blood creature, while the fuath is an intangible spirit than only occasionally turns solid.
-McLaughlin, M. T. 2018. Songs between worlds: enchantment and entrapment in the Irish otherworld song tradition.
-Watson, E.C., 1908. Highland Mythology. The Celtic Review, pp.48-70.
-Goodrich-Freer, A., 1899. The Powers of Evil in the Outer Hebrides. Folklore, 10(3), pp.259-282