Nøkken or Puken as he sometimes is called, is a dangerous and manipulative creature from Norwegian folklore. The word ''Nøkk'' comes from old Norse meaning seahorse.
He roams in rivers, small waters and seas. In tales he live in waters with water lilies, so it would be easier to lure people closer to the water, especially children who wanted to pick the lilies.

Nøkken is a shape-shifter, for women he would turn into a handsome young man with a fiddle, which he would use to play beautiful, seductive music to draw the women closer. Another shape, is that of a beautiful white horse with opal black eyes, the mane on the horse would almost be like thick fog and he would almost glow of a white shimmer.
Nøkken could also transform into an old wood boat or an old tree stump.
However, his real apparel is hideous, as he is covered with sea grass and his eyes are glowing yellow. He has a huge mouth with sharp teeth, and his skin is like that of a drowned man who has been long underwater.

It is said that if one is captured by Nøkken, one should say his name and he will disappear into the waters again.

POSSIBLE INFO FOR LATER:

There is a legend from a place called Härjedalen in Sweden, that Näcken (Swedish name) can give fiddle players the gift of being the best fiddle player there ever was - though Näcken is malicious and there's a catch. A man once asked for this and gladly strolled home with his newly gained skill and prepared for the festival that was taking place the very same night. He played and played, and people laughed and were happily dancing all night long. But the fiddle man couldn't stop playing, and as long as his magic melodies played the people could not stop dancing no matter how tired or hungry they were. The people literally danced until they feet bled and eventually they did die - and the fiddle man too. Legend says that one of the songs the fiddle man was given Näcken, is today the "national anthem" of Härjedalen.