Cafall is Bran Davies' dog, a black and white sheepdog with silver eyes. He is referred to in the Grail verses as "the silver eyes that see the wind," and he could always see things that others did not. He found a lost Will on a hillside on Cader Idris, kept him from falling, and provided the trigger for Will to remember his mission as an Old One. He chased off milgwn, He was shot by Caradog Prichard, acting as an agent of the Dark.
In Arthurian mythology, Cafall was the name of King Arthur's dog, though it is worth pointing out that cafall is also an old Welsh word for "horse", probably derived from the Latin caballus, meaning "packhorse".