Sweden has one of the highest numbers of lakes and waterways in Europe. Because of this, Swedish folklore is filled with supernatural beings calling the woodland lakes, dark ponds and rapid waterways their homes. These can be benelovent guardians, elemental beings of great power or creatures of darkness and of ill intent. The most iconic of them all is probably the evil, or at least mischievous, water spirit known as Näcken.
Näcken usually appears in the guise of a man or boy, whose most distinguishing features are his dark, seemingly bottomless eyes, his long darkgreen hair, and the fact that he is most often seen sitting with his fiddle or flute next to a brook or pond, playing the most hauntingly beautiful tunes. His melodies drain the will and he can hypnotize his unlucky audience to follow him into the dark waters, or charm them into a neverending dance from which their dazed minds will never wake. One should stress, however, that descriptions of him are numerous, varied, and sometimes highly atypical (as are descriptions of all creatures of folklore) .
As with most other creatures of fairykind, Näcken can be bound by steel. That is why you should always stick your knife into the ground by the side of the lake if there are many water lilies blooming in the water, as this is a sign that the sinister fiddler is nearby.