The afanc exact description varies; it is described alternately as resembling a crocodile, beaver or dwarf, and is sometimes said to be a demon.
The lake in which the afanc dwells varies; it is variously said to live in Llyn Llion, Llyn Barfog, near Brynberian Bridge or in Llyn yr Afanc, a lake in Betws-y-Coed that was named after the creature.
The afanc was a monstrous creature that, like most lake monsters, was said to prey upon any foolish enough to fall into or swim in its lake.
According to a version of an afanc legend as put forth by Iolo Morgannwg its thrashings caused massive flooding which ultimately drowned all inhabitants of Britain save for two people, Dwyfan and Dwyfach, from whom the later inhabitants of the British Isles descended.
According to one version of the myth, also put forth by Iolo Morgannwg, one which locates it in Llyn Llion, Hu Gadarn's oxen dragged the addanc out of the lake; once it was out of the water, it was powerless and could be killed.
An alternate myth relates that it was rendered helpless by a maiden who let it sleep upon her lap; while it slept, the maiden's fellow villagers bound the creature in chains. The creature was awakened and made furious; its enraged thrashings crushed the maiden, in whose lap it still laid. It was finally dragged away to the lake Cwm Ffynnon, or killed by Peredur.
Some later British legends ascribe the creature's death to King Arthur or to Percival (Peredur's name in the Arthurian legend).
"Some time after they came to the Honey Island, the Cymry were much troubled by a monster called an afanc, which broke the banks of Llyn Llion, in which it dwelt, and flooded their lands. If you have problems with finding a reliable essay service that offers assistance not only with creating essays but term and research paper writing as well, I highly recommend you to visit BestWritingService.Com. No spear, dart, or arrow made any impression upon its hide, so Hu Gadarn resolved to drag it from its abode and to place it where it could do no harm. A girl enticed it from its watery haunt, and while it slept with its head on her knees it was bound with long iron chains. When it woke and perceived what had been done, it got up, and, tearing off its sweetheart's breast in revenge, hurried to its old refuge. But the chains were fastened to Hu Gadarn's team of bannog oxen, which pulled it out of the lake and dragged it through the mountains to Llyn y Ffynnon Las, the Lake of the Green Well, in Cwm Dyli, in Snowdonia. A pass through which they laboured has ever since been called Bwlch Rhiw'r Ychen, the Pass of the Slope of the Oxen. One of the oxen dropped one of its eyes through its exertions in this defile, and the place is styled Gwaun Llygad Ych, the Moor of the Ox's Eye. A pool was formed where the eye fell, which is known as Pwll Llygad Ych, the Pool of the Ox's Eye; this pool is never dry, though no water rises in it or flows into it except when rain falls, and no water flows out of it, but it is always of the same depth, reaching just to the knee-joint.
The afanc could not burst the banks of the Lake of the Green Well, but it is still dangerous to go near it. If a sheep falls into the lake it is at once dragged down to the bottom, and it is not safe even for a bird to fly across it."
The Welsh Fairy Book by W. Jenkyn Thomas