"Beaver." A kind of crocodile or giant beaver, but it was originally, according to John Rhŷs, a monster in human form. It was believed to drag people into the water and to cause flooding. King Arthur is reputed to have slain one in Llyn Barfog. The name is found in Llyn yr Afanc (Beaver Pool), a pool on the river Conwy, above Bettws y Coed. The story goes that it was a girl that enticed the afanc to come out of his abode, so as to be bound by iron chains, whilst he slumbered with his head on her knees, and with one hand on her breast. When he awoke and perceived what had been done to him, he rushed back to his pool, taking with him in his claw the breast of the maiden. The chain was fastened to oxen that pulled him out of the pool. A dispute arose among some of the assembled, each asserting that he had pulled harder than anybody else. And while they were arguing, the afanc silenced them by saying:

Oni bae y dai ag a dyn
Ni daetha'r afanc byth o'r llyn

Had it not been for the oxen pulling,
the afanc had never left the pool.

Another afanc lived in Llyn Syfadon, but the undertaking to take it away failed, and the afanc remained in his lake.

The Irish cognate is Abhac, which is derived from abha, "river."



  • Bonnerjea, Biren. (1920). A Dictionary of Superstitions and Mythology. Thomson Gale.
  • Eberhart, George M. (2002). Mysterious Creatures: A Guide to Cryptozoology. Santa Barbara: ABC-CLIO, Inc.
  • Rhŷs, J. (1901). Celtic folklore, Manx and Wales. Vol. 1. Oxford: Clarendon Press, pp. 130-131, 134-135.