Tyrfing was a sword that appears in the poem from the Elder Edda called The Waking of Angantýr , and in Hervarar saga. In Richard Wagner's opera, King Alberich gave it to Odin.

Tyrfing was a cursed sword, and bore the misfortune that each time it was unsheathed, a man must die.

Sigrlami, a king descended from Odin, forced the Dwarves to forge the sword Tyrfing (ripper). The Dwarves laid on it a curse, that it should bring death to its bearer, that no wound made by it should be healed and that three deeds of woe should be wrought by it.

Sigrlami was slain by Arngrim , who inherited the sword. Eyfura, his wife, had twelve sons, all of whom become Vikings. Angantyr , the eldest, and his brothers, are eventually all slain at Samsø, by the Swedish champion Hjalmar, and his sworn brother Orvar-Odd; but Hjalmar, being wounded by Tyrfing, has only time to sing his death-song before he dies, and asks Orvar-Odd to bring his body to Ingeborg at Uppsala.

Angantyr's daughter, Hervor (by his wife Tofa) is brought up as a bond-maid, in ignorance of her parentage. When at last she learns it, she arms herself as an shieldmaiden, and goes to Munarvoe in Samsø, in quest of the dwarf-cursed weapon.