Icelandic folktales are populated by sea monsters and beasts. Surrounded by gelid currents carrying waters from the Arctic, in ancient times those forced to go out at sea would have had little hopes for survival if anything went wrong, and that includes facing a large animal like a whale. Whales were often seen as evil, some more than others. The most dangerous and malignant of these beasts were named gropued under the term Illhveli (literally wicked or evil whales).
The Nautshval, which translate as cow-whale, is one of the Illhveli that once filled the heart of every Icelandic fisherman with fear. This particular one, the second biggest of them all, will show up if its name is said out loud.
The nautshval is a toothed whale. It has a face with large nose with two big rounded nostrils that work as a fog horn. Male nautshval have large heads, that like in bulls, present a type of horn, in this case two long nodules. Some has described this whale as having a wormlike body, others said that instead of fins it has long appendixes resembling legs. Most agree, however, that the nautshval name was given not because of its appearance, but for the terrifying bull-like bellow it makes when hungry, a sound like the loud buffing of a maddened bull.
Nautshvals never swim near the coast, but their call reverberates over long distances. When it reaches land, its vibrations shake the ground. For those unfortunate enough to be out at sea when the nautshval calls, the sound may knock the oars out of their hands or make a boat's hull crack. Going out to sea is forbidden if the nautshval bellowing has been recently heard.
As will all evil whales, the nautshval delights in killing people and scuttling smaller boats, but it has a particular fondness for beef. The whales are attracted to cattle on board ship. It is said, that in the waters out of Grimsey, one nautshval harassed a small vessel until they released the one cow on board. The animal promptly dove into the sea; the bellow of a nautshval is hypnotic to cattle. It compels them to run off cliffs and headlong into the sea. After the Grimsey incident, cattle had to be locked up for days until the nautshval spell wore off. Hence, cow-herding was strongly discouraged in areas where nautshvals had been heard. At times, out of desperation, small coastal communities sacrificed one bull or cow to satisfy the nautshval hunger, making it safe to go out to sea again.
Hunting nautshvals was a nearly impossible and highly risky endeavor, and little was gain by trying. Like it's the case with all evil whales, the meat of this monster is uneatable, so few were the intrepid souls who ever dare go after a nautshval.
-Jón Baldur Hlíðberg, Sigurður Ægisson. 2008. Meeting with Monsters: An Illustrated Guide to the Beasts of Iceland. JPV.
-Guðrún Bjarkadóttir. 2010. Icelandic mammal name: Their history and origins, Master Thesis. University of Iceland. Department of Icelandic Studies and Culture.