The Element Encyclopedia of Witchcraft: The Complete A-Z for the Entire Magical World - Judika Illes 2005
The giants (Jotuns) of Norse mythology survive as the trolls and troll-hags of Norwegian folklore and fairy tales. Another name for them is haugfolk (“people of the mounds,” similar to the sidhe). These spirits inhabit a hidden world, but most often reveal themselves to people in forests or on mountains, their preferred territory. In some regions, trolls own mountains, only permitting people access to them during the brief Northern summer.
Many troll-hags are beautiful although they are simultaneously large, fierce, wild, and potentially dangerous. Many also possess profound magical and botanical knowledge and the word “troll-hag” is also used to indicate “witch.”
In the Norwegian fairy tale, Polar Bear King Valemon, a troll-hag bewitches the king, transforming him into a bear and forcing him to marry her. She is a powerful and independent entity, beholden to no one. In the 1991 Swedish film adaptation of the tale, The Polar Bear King, the troll-hag has become a beautiful but evil conventional fairy-tale witch and is explicitly identified as a liege of Satan.
See Giants, Gyre Carlin; DICTIONARY: Trollkvinna; FAIRY-TALE WITCHES: Naturespirit Fairies: Sidhe; Trolls.