In Norse mythology

Norse mythology

Norse mythology, a subset of Germanic mythology, is the overall term for the myths, legends and beliefs about supernatural beings of Norse pagans. It flourished prior to the Christianization of Scandinavia, during the Early Middle Ages, and passed into Nordic folklore, with some aspects surviving...

, Ótr (alternately: Ott, Oter, Otr, Ottar, Ottarr, Otter) is a dwarf. He is the son of the king Hreidmar

Hreidmar

In Norse mythology, Hreiðmarr is the avaricious king of the Dwarves, who captured three gods with his unbreakable chains. He was father of Fafnir, Ótr and Regin. He owned a house of glittering gold and flashing gems built by Regin and guarded by Fafnir. After Otr was accidentally killed by Loki,...

 and the brother of Fafnir

Fafnir

In Norse mythology, Fáfnir or Frænir was a son of the dwarf king Hreidmar and brother of Regin and Ótr. In the Volsunga saga, Fáfnir was a dwarf gifted with a powerful arm and fearless soul. He guarded his father's house of glittering gold and flashing gems...

 and Regin

Regin

Reginn, often Anglicized as Regin, in Norse mythology, was the son of Hreiðmarr and foster father of Sigurd. His brothers are Fafnir and Ótr. When Loki mistakenly kills Ótr, Hreiðmarr demands to be repaid with the amount of gold it takes to fill Ótr's skin and cover the outside. Loki takes this...

.

According to the Prose Edda

Prose Edda

The Prose Edda, also known as the Younger Edda, Snorri's Edda or simply Edda, is an Icelandic collection of four sections interspersed with excerpts from earlier skaldic and Eddic poetry containing tales from Nordic mythology...

, he could change into an any form, and used to spend his days in the shape of an otter

Otter

The Otters are twelve species of semi-aquatic mammals which feed on fish and shellfish, and also other invertebrates, amphibians, birds and small mammals....

, greedily eating fish. Ótr was slain accidentally by Loki

Loki

In Norse mythology, Loki or Loke is a god or jötunn . Loki is the son of Fárbauti and Laufey, and the brother of Helblindi and Býleistr. By the jötunn Angrboða, Loki is the father of Hel, the wolf Fenrir, and the world serpent Jörmungandr. By his wife Sigyn, Loki is the father of Nari or Narfi...

. Hreidmar demanded a large weregild

Weregild

Weregild was a value placed on every human being and every piece of property in the Salic Code...

 for Ótr's death, namely to fill Ótr's skin with yellow gold, and to then cover it entirely with red gold. When the skin was covered, one whisker was still protruding, forcing Loki

Loki

In Norse mythology, Loki or Loke is a god or jötunn . Loki is the son of Fárbauti and Laufey, and the brother of Helblindi and Býleistr. By the jötunn Angrboða, Loki is the father of Hel, the wolf Fenrir, and the world serpent Jörmungandr. By his wife Sigyn, Loki is the father of Nari or Narfi...

 to give up the ring Andvarinaut

Andvarinaut

In Norse mythology, Andvaranaut is a magical ring capable of producing gold, first owned by Andvari.The mischievous god Loki tricked Andvari into giving Andvaranaut to him...

 to hide it. The ring had been stolen from, and cursed by, the fish-dwarf Andvari

Andvari

In Norse mythology, Andvari is a dwarf who lives underneath a waterfall and has the power to change himself into a fish at will. Andvari had a magical ring Andvarinaut, which helped him become wealthy....

. Greed for this cursed treasure ultimately caused the deaths of Hreidmar and his two surviving sons: Hreidmar was killed by Fafnir, who transformed into a lindworm

Lindworm

Lindworm in British heraldry, is a technical term for a wingless bipedal dragon often with a venomous bite.-Etymology:In modern Scandinavian languages, the cognate lindorm can refer to any 'serpent' or monstrous...

, and the other two were slain Sigurd

Sigurd

Sigurd is a legendary hero of Norse mythology, as well as the central character in the Völsunga saga. The earliest extant representations for his legend come in pictorial form from seven runestones in Sweden and most notably the Ramsund carving Sigurd (Old Norse: Sigurðr) is a legendary hero of...

's sword Gram

Gram (mythology)

In Norse mythology, Gram is the name of the sword that Sigurd used to kill the dragon Fafnir.It was forged by Wayland the Smith and originally belonged to his father, Sigmund, who received it in the hall of the Volsung after pulling it out of the tree Barnstokk into which Odin had stuck...

.