British Goblins: Welsh Folk-lore, Fairy Mythology, Legends and Traditions
CHAPTER III.
Spectral Animals--The Chained Spirit--The Gwyllgi, or Dog of Darkness--The Legend of Lisworney-Crossways--The Gwyllgi of the Devil's Nags--The Dog of Pant y Madog--Terrors of the Brute Creation at Phantoms--Apparitions of Natural Objects--Phantom Ships and Phantom Islands 167