Regin

Regin is a master smith, son of Hreidmar and brother of Fafnir and the slain Otr, who becomes foster-father to the hero Sigurd. Cheated of his share of Andvari's cursed gold when Fafnir takes the hoard and turns into a dragon, Regin reforges the broken sword Gram and goads young Sigurd to slay Fafnir on his behalf. He bids Sigurd roast the dragon's heart for him, scheming to murder the boy and seize the treasure. But Sigurd burns his thumb, tastes the blood, and the birds warn him; he beheads Regin instead.