Wikipedia
A huldra is a seductive forest creature found in Scandinavian folklore. (Her name derives from a root meaning "covered" or "secret".) In Norwegian folklore, she is known as Huldra. She is known as the skogsrå (forest spirit) or Tallemaja (pine tree Mary) in Swedish folklore, and Ulda in Sámi folklore. Her name suggests that she is originally the same being as the völva Huld and the German Holda.
Males, called Huldrekall (sg.), also appear in Norwegian folklore. This being is closely related to other underground dwellers, usually called tusser. Whereas the female hulder is almost invariably described as incredibly, seductively beautiful, the males of the same race are often said to be hideous, with grotesquely long noses.
Usage examples of "hulder".
The one that had to be played quietly, with the bow moving lightly over the strings, was the hulder in yonder fog, calling together her cattle, where no one but herself could see.
Out of the deep forest, down from the mountains, up from rivers and fjords they believe that the magical creatures come: the hulders, the nisser, the fosse-grimmer, the nokker.