The njuggle is a waterhorse and a shapeshifter in the folklore of the Shetland Isles.
The njuggle can take the form of a splendid Shetland pony. It used to hide under the mills and stop the wheel or tirl from turning by rubbing its back against it. The only way to get rid of it was to throw a burning peat down into the area where the wheel sat, known as the underhoose.
Like its counterparts, the njuggle is known to entice weary travellers to sit on its back then rush into the nearest loch where they would be drowned.