A mischievous Manx water-horse. It can assume human shape but is unable to hide his horse's ears. The glashtin sometimes leaves his native element to associate with land animals of the same class. It can be compared with the Scottish kelpie and each uisge, the Irish aughisky, and the Welsh ceffyl dwfr. Another Manx water-horse is the cabyll-ushtey.
- MacKillop, James. (2004). Dictionary of Celtic Mythology. New York: Oxford University Press, Inc.
- Train, J. (1845). An historical and statistical account of the Isle of Man, from the earliest times to the present date. Vol. 2. Douglas: Mary A. Quiggin, p. 147.