What is "noekk"

Noekk is a German progressive doom metal band that is a collaboration of two then former Empyrium members ( Markus Stock, a.k.a. Ulf T. Schwadorf, and Thomas Helm). The origin of the band's name is supposed to come from a water creature that was able to transform into a beautiful white horse. When the proud stallion eventually got a human to mount it, it dashed into the dark waters and drowned the victim. According to the band, the Noekk demanded an annual human sacrifice, but this is not a part of the traditional folklore. Noekk has released three full-length albums on Prophecy Productions.