will make the creature visible. Peredur ventures into the cave and with the aid of the stone, pierces the Addanc before beheading it. When the three chieftains arrive at the cave they state that it was predicted that Peredur would kill the Addanc. Some legends ascribe the creature's death to King Arthur. Close to Llyn Barfog in Snowdonia is a hoof-print petrosomatoglyph etched deep into the rock Carn March Arthur "Stone of Arthur's Horse", which was supposedly made by King Arthur's mount, Llamrei, when it was hauling the addanc from the lake. Iolo Morganwg According to a version of an afanc legend as put forth by the famous writer of myths and folklore Edward Williams known as Iolo Morganwg, 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 Prydain descended. According to one version of the myth, also put forth by Iolo Morganwg, Hu Gadarn's oxen dragged the afanc out of the lake; once it was out of the water, it was powerless and could be killed. This version locates the creature in Llyn Llion. Orthography The correct rendering of this name in Modern Welsh depends on the specific source. The Middle Welsh avanc of Llyn Barfog is afanc in Modern Welsh, a word which is now used to mean "beaver". The form avanc/afanc is also used in the Red Book of Hergest and most other medieval sources. In the Middle Welsh version of Peredur's tale in the White Book of Rhydderch, the creature in the cave is called the addanc. Afanc is by far the most common spelling. In popular culture An afanc appears in Silver on the Tree, the final book in Susan Cooper's The Dark is Rising sequence. In the Merlin episode "The Mark of Nimueh", the villainess Nimueh creates an afanc by molding a small figure out of clay and hatching it from an egg-like container. The creature spreads a deadly disease across Camelot through the water it inhabits, until Merlin and Arthur manage to destroy it. In China Miéville's 2002 book The Scar, the floating city-state of Amarda summons an avanc, attaching it to the city and using its huge pulling-power to cross the ocean. In the October Daye series by Seanan McGuire, afanc are a marsh creature about the size of a cow with fur, scales, and a