The glashtin is said to be a goblin that appears out of its aquatic habitat, to come in contact with the island folk; others claim it takes the shape of a colt, or equate it to the water horse known locally as cabbyl-ushtey.
[9][a] In the Manx English dialect, "Glashan, glashtan, glashtin" as 'hairy goblin' is the primary (and most detailed) entry given in Moore's posthumous dictionary (1924), completed in collaboration with Morrison and Goodwin.
[13] Welsh scholar Rhys also concurred, saying that his "informants" were at odds, some of them regarding the "glastyn" as the Manx version of the brownie, while others were adamant it was "a sort of grey colt, frequenting the banks of lakes at night".
Recent literature embracing this notion claims that the equine glashtin assumes human form at times, but betrays his identity when he fails to conceal his ears, which are pointed like a horse's.
[16] One modern fairy tale relates how a fisherman's daughter living in Scarlett outwitted the foreign-tongued "dark and handsome" stranger whom she recognized as glashtin by his horse's ears.
In one passage, Train claims the glashtin to be a water-horse, and that this sea-glashtin[22] would at one time emerge from his marine habitat, mingling with the local land-roving ponies, and cross breed to produce foal.
[5] German mythographer Karl Blind noted that Manx glashtin or elashtan "attacks lonely women" as is the case with the Shetlandic nuggle and the Scottish kelpie.
[12] Charles Roeder records a similar tale of a woman who loosened her apron-string to rid herself of the glashtin clung on her apron, and he spoke these words: 'Rumbyl, rumbyl, cha vel ayms agh yn sampyl' (The edge or skirt of the garment, I have but the sample).
[28] In the aforementioned modern fairy tale, on a stormy night in Scarlett, the girl Kirree Quayle gave refuge to a dark, handsome stranger, but afterwards recognized him be a glashtin, deducing from his horse ears.
She resisted his temptation of a strand of pearls dangled before her, and when grabbed she let out a scream, causing the red cockerel to crow, prematurely announcing the break of dawn, scaring the glashtin away.
The story-telling woman described a creature or being which assisted her as farmhand, performing the tasks of rounding up sheep from the fold, or threshing stalks of corn left unbundled.