Lady of the Lake

The mysterious Lady of Loch Beathadach. She lies submerged deep beneath the cold waters, rarely coming to the surface and then only to briefly address her visitors. Those who converse with her speak not of what they witness, nor of what is said to them. Most who seek an audience with her perish on the icy waters, their rowboats drifting aimlessly back to shore laden with gore.
It is well known that she predates the Beathadach and their construction of the Mor Fiodh. The Beathadach know her as "Nyx" and seem to hold her in reverence. They are able to converse with her with more freedom than is afforded to humankind, though they also do not share what they learn with humans.
In the Saga of Artweg, it is said that a young King Artweg conversed with her and was entrusted with the legendary sword Caledfir. Upon Artweg's death, it is said that his most trusted knights were charged with returning Caledfir to her care. With the instruction to throw the sword into the blue depths of the loch, it is said that a hand with two opposed thumbs rose from the water to catch the sword by the blade, then sank back into the depths.