Galley-Trots, a.k.a. Gally-Trots, White Hounds, etc., are supernatural canines, similar to Hell Hounds or Phantom Black Dogs, which are believed to live underground in hollow hills or "fairy mounds".
Appearance: Galley-Trots appear as large hounds the size of bulls, having shaggy, white fur and red ears and eyes.
Lore: Galley-Trots haunt abandoned ruins and are believed to guard treasure. Anyone who trespasses on their turf may be attacked or given chase by the beasts. Additionally, Galley-Trots were believed to make appearances outside of homes where a person would soon die.
Powers: Galley-Trots are omens of death. Galley-Trots may have supernatural abilities such as to become invisible or to disappear.
Defense Against Galley-Trots: Unknown. Due to their potential connections to fairy hounds, iron objects and salt may prove effective against warding off the creatures.
Mysterious Creatures: A Guide to Cryptozoology, Volume 1 By George M. Eberhart
Giants, monsters, and dragons: an encyclopedia of folklore, legend, and myth By Carol Rose