A hideous hag who haunts Welsh families, and is also associated with specific places.
In appearance she has matted black hair, overlong arms, black teeth and a hooked nose. A traditional Banshee, she haunts the old Welsh families, warning of death. She would cry out as if she was lamenting the person who was going to die. For instance she would cry ‘Oh my husband! my husband!’ if a man was to die.
She is mentioned in Celtic Folklore by John Rhys, he considers that she may be an ancient goddesses, as similar figures, such as Black Annis and the Cailleach Bheur, appear throughout the British Isles. These figures may be a remnant of a widely worshiped dark goddess.
The Gwarach-y-rhybin is also said to haunt Pennard Castle and the banks of the River Dribble.