What is "nuggle"

A Nuggle, or Neugle, was a mythical water horse of primarily Shetland folklore where it was also referred to as a shoepultie or shoopiltee on some parts of the islands. A nocturnal creature that was always of a male gender, there were occasional fleeting mentions of him connected with the Orkney islands but he was more frequently associated with the rivers, streams and lochs of Shetland. He was easily recognised by his distinctive wheel-like tail and, unlike his evil counterparts the Each-uisge or the Nuckelavee, had a fairly gentle disposition being more prone to playing pranks and making mischief rather than having malicious intents.