The Cŵn Annwn are the spectral hounds of Annwn, the otherworld of Welsh myth, marked by their red ears. They are presided over by Arawn, king of Annwn, or by Gwyn ap Nudd as king of the underworld.
Their growling is loudest when they are at a distance, and grows softer and softer as they draw near. To hear the howling of these huge dogs is a portent of death. They are associated with the Wild Hunt, and with migrating geese, whose honking in the night was likened to the barking of dogs.