On his journey he meets a maiden who states that the Addanc will slay Peredur through cunning, as the beast is invisible and kills his victims with poison darts.
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.
In the Middle Welsh version of Peredur's tale in the White Book of Rhydderch, the creature in the cave is called the addanc.
[2] An afanc appears in Silver on the Tree, the final book in Susan Cooper's The Dark is Rising sequence.
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.
[3] In the October Daye series by Seanan McGuire, afanc are a marsh creature about the size of a cow with fur, scales, and a "disturbing" number of teeth.
In The Lord of the Rings Online video game, the culture of Dunland, sparsely described by J. R. R. Tolkien, is heavily based on the Welsh mythology.