The otter holds a pivotal place in Norse myth through the tale of the otter's ransom. Otr, a son of the magician Hreidmar, took the shape of an otter to fish, and was killed by Loki, who took him for a real animal. To atone, the gods were forced to fill and cover the otter's flayed skin with gold, and Loki seized the treasure of the dwarf Andvari to do it, gold that carried Andvari's curse, and with it the ring that would bring ruin on all who held it, setting in motion the whole tragic cycle of the Volsungs and the Nibelungs. The otter's death is the small beginning of a vast doom.
The sea otter offers a genuine modern conservation story distinct from either myth above: hunted for its exceptionally dense fur, the warmest of any mammal, to the edge of extinction by the early twentieth century, the species has been the subject of sustained protection and reintroduction efforts since, and its recovery matters ecologically beyond the animal itself, since sea otters are a keystone species whose predation on sea urchins keeps kelp forests from being stripped bare, so the health of an entire coastal ecosystem tracks the otter population. A species distinction underlies the two otter stories told in this pair of articles: Otr of the Norse myth would have been a Eurasian otter, Lutra lutra, a freshwater animal of European rivers, entirely different from the sea otter, Enhydra lutris, discussed below, a North Pacific marine species unknown to the Norse world that produced the tale of Andvari's cursed gold.