What is "glashtyn"

Glashtyn (, glashan, glaistyn, glastyn; pronounced ) is a legendary creature from Manx folklore. The word glashtin is thought to derive from Celtic , meaning "stream", or sometimes even the sea.

By some accounts, the glashtin is a goblin that appears out of its aquatic habitat, to come in contact with the island folk; others equate it to the water horse known locally as "cabyll-ushtey".