Deep in the lakes and pools of Eryri (Snowdonia) lives a creature that is neither fully dragon nor fully beast. The Afanc is one of the most distinctive monsters in Welsh folklore — a water-dwelling terror said to cause floods, drag livestock into the depths, and, in some versions, possess a form that is half dragon and half beaver.
Unlike the more ethereal Ceffyl Dŵr, the Afanc is a physical, destructive presence. Stories place it in Llyn yr Afanc near Betws-y-Coed, in Llyn Tegid (Bala Lake), and in other deep waters of north Wales. Wherever it appears, the result is the same: the land floods, people suffer, and heroes must find a way to remove it.
The nature of the Afanc
Descriptions vary. Some accounts portray the Afanc as a giant beaver-like creature with the strength to uproot trees and reshape rivers. Others give it more draconic features — a long body, powerful limbs, and a capacity for violence that feels closer to the dragons of Welsh legend. In every version it is dangerous, territorial, and almost impossible to kill outright.
The most famous story involves the hero Hu Gadarn (or, in later retellings, other figures). The Afanc cannot be slain by ordinary means, so it must be lured from the water using a beautiful maiden as bait. Once on land, it is bound with chains and dragged by oxen to a new home in a mountain lake where it can do less harm. The effort is so great that the oxen leave their mark on the landscape — one of the many places in Wales where folklore and geography are said to meet.
Afanc, water, and Welsh identity
Water has always been powerful in Welsh mythology. From the Ceffyl Dŵr that lures travellers to their deaths to the Lady of the Lake at Llyn y Fan Fach, the lakes and rivers of Wales are rarely empty. The Afanc represents the more destructive side of that power — the flood, the sudden loss, the thing that lives beneath the surface and cannot be reasoned with.
Its association with Eryri also links it to the broader dragon lore of the region. The Red Dragon of Dinas Emrys, the Afanc of the lakes, and the other water beings of north Wales form a connected web of stories in which the landscape itself is alive with myth.
A creature that refuses to vanish
Like many Welsh monsters, the Afanc has never fully disappeared from local memory. Place names preserve it. Local guides still point out the lakes associated with the legend. And for anyone who has walked the quieter paths of Eryri on a still day, it is not difficult to understand why people once believed something large and ancient might still move beneath the water.
Read more Welsh legends in our lore library, or meet the water horse in our Ceffyl Dŵr story.