This post was originally some notes for my book, but after my lead turned out to be a red herring, I decided to make it a short Tumblr post instead.
The Alfanc is a Welsh water demon associated with the ILyn Cwm Ffynnon in Conway and the ILyn Barfog in Aberdovey, the first called “the lake Of The Green Well” and the former called “The Bearded Lake”.
The ILyn Cwm Ffynnon particularly had always been a place of mystery and myth, stories of stags or goats sinking themselves into it to hide from predators - leaving only their horns above the water, or of strange people leaving the pool for errands before sinking back into its depths never to be seen again surround it. Bedgelert in the Brython reported the pond to be 300 feet deep, though I cannot be sure of the accuracy of his claim, especially considering the stories of stag horns still visible when the stag had been standing presumably at the bottom of the pond. But the idea that the pond is far deeper than it's meant to be is a recurring theme throughout the many myths surrounding it, much like a portal.
“The Afanc am I, who, sought for, bides
In hiding on the edge of the lake ;
Out of the waters of Syfad'on Mere
Was he not drawn, once he got there.
So with me : nor wain nor oxen wont to toil
Me to-day will draw from here forth.”
- Lewis Glyn Cothi, Celtic folklore by John Ryhs, pg 135.
The Afanc is said to be a crocodile who lives in the depths of the pond, but that depiction was through word of mouth rather than historical evidence until Mr. Pughe of Aberdovey wrote a paper on The Alfanc in 1853.
“The lovers of Cambrian lore are aware that the Triads in their record of the deluge affirm that it was occasioned by a mystic Afanc y ILyn, crocodile - of the lake, breaking the banks of ILyn ILion, the lake of waters; and the recurrence of that catastrophe was prevented only by Hu Gadarn, the bold man of power, dragging away The Afanc by aid of his Ychain Banawg, or large horned oxen.”
Mr. Pughe, Celtic folklore by John Ryhs, pg 142.
He mentions Llyn Llion or The Lake Of Waters, where the “mountaineers of Aberdovey” in his words claimed the mythical King Arthur saved them from a creature Mr. Pughe associated with the Afanc.
The Afanc is also associated with romance and a young woman who was said to have enticed him out of the waters so she could trick and chain him in iron. She attached him to an oxen who pulled him out of the lake, during which he had been holding her breast and with claws dug into the flesh, ripped it from her.
This story mirrors the previous and another told about the ILyn Cwm Ffynnon where a beautiful nymph is caught by a man and she calls for her father, an old man who appears from under the water. He wants to marry her and after some consideration, she agrees, her father however demands he agree to never hit her. The man agrees yet after taking her home goes back on his word.
This theme of the Alfanc being abused by a mortal lover is the basis of their myth. They are the demon of the lake seduced by the human siren, the lover's naivety.
Whether the Alfanc is indeed a singular demon, the first who inspired the later myths, I cannot be sure. Regardless they are a character of the repeated folktales surrounding the lakes of Conway, a faerie who must be accounted for in the record of the Elphame folk.
