The Shellycoat is a Scottish bogeyman who haunts the rivers and streams.
The name comes from the coat of shells these creatures are said to wear, which rattle upon movement.
Jacob Grimm stated in his Deutsche Mythologie that the Scottish goblin Shellycoat is one and the same as the German Schellenrock, that is bell-coat:
“A pück [home-sprite] served the monks of a Mecklenburg monastery for thirty years, in kitchen, stall and elsewhere; he was thoroughly good-natured, and only bargained for 'tunicam de diversis coloribus, et tintinnabulis plenam.' [a "parti-coloured coat with tinkling bells"] In Scotland there lived a goblin Shellycoat, and we saw (p. 465) that the dwarfs of the Mid. Ages also loved bells [schellen; and schellenkappe is Germ. for cap and bells]. The bells on the dress of a fool still attest his affinity to the shrewd and merry goblin (fol, follet); see Suppl.
The shellycoat is covered with shells, with long arms and fingers, a large flat nose and thin, wet hair. A shellycoat's body is always damp and clammy. It rattle when he moves, announcing his presence and often smells slightly of stagnant water.
The shellycoat shares many of the traits of the Brag, Kelpie and Nix. He is playful, but rather harmless. One of his favorite trick is to mislead wanderers and put them on the wrong track.
Many places on the coast of Scotland have names that reference the shellycoat. Supposedly, shellycoats are particularly fond of the area around the river Hermitage, in Liddesdale.
"Shellycoat, a spirit who resides in the waters, and has given his name to many a rock and stone the Scottish coast, belongs to the class of bogles. When he appeared, he seemed to be decked with marine productions, and in particular with shells, whose clattering announced his approach. From this circumstance he derived his name. One of his pranks is thus narrated:--Two men, on a very dark night, approaching the banks of the Ettrick, heard a doleful voice from its waves repeatedly exclaim, "Lost! Lost!" They followed the sound, which seemed to be the voice of a drowning person, and, to their infinite astonishment, they found that it ascended the river. Still they continued, during a long and tempestuous night, to follow the cry of the malicious sprite; and arriving, before morning's dawn, at the very sources of the river, the voice was now heard descending the opposite side of the mountain in which they arise. The fatigued and deluded travellers now relinquished the pursuit, and had no sooner done so than they heard Shellycoat applauding, in loud bursts of laughter, his successful roguery. The spirit was supposed particularly to haunt the old house of Gorinberry, situated on the river Hermitage, in Liddesdale."