He is easily recognised by his distinctive wheel-like tail and, unlike his evil counterparts the each-uisge or the nuckelavee, has a fairly gentle disposition being more prone to playing pranks and making mischief rather than having malicious intents.
[10] Similar equine type creatures are: the evil Each-uisge from the Gaelic folklore of the Scottish Highlands;[19] the Tangies that haunt the coastline and sea shores but reside in the ocean depths;[20] and the Norwegian nøkk.
[8] The trademark tail made him easily recognisable[21] despite his attempts to hide it between his hind legs[8] so he tended to stay out of sight except at night or just as the sun set in the twilight hours.
[21] Additionally, unlike other corresponding creatures, he was of a gentle disposition, more likely to instil fear rather than attacking islanders although some tales suggest otherwise;[21] according to the author and folklorist Jessie Saxby "he was a more feeble sort".
[23] If the nuggle had successfully tricked an unsuspecting passer-by into mounting him, usually by pretending to be tame and standing tranquilly at the side of a path, he would immediately make for the nearest deep water.
[25] Writing in the Journal of American Folklore during 1918 the anthropologist James Teit hypothesises that, as is common with most supernatural creatures, nuggles were thought to be fallen angels.