Introduction
Fafnir was a son of Hreidmar, described as the strongest and grimmest of his brothers. When his father claimed the cursed gold ransom entirely for himself, Fafnir's greed for it overcame family loyalty.
Family
Dragon of the Cursed Hoard
Fafnir murdered Hreidmar in his sleep to seize the gold, refusing to share any of it with his brother Regin. Consumed by his possessiveness, he withdrew to a wasteland called Gnitaheath and transformed into a monstrous dragon (or wore a helm of terror and took on a serpentine nature, in the saga's own account) to guard the hoard alone. Years later, urged on by his own embittered brother Regin, the young hero Sigurd dug a pit in Fafnir's path and stabbed him from below as he crawled to drink, fulfilling the next stage of Andvari's curse.
The Volsunga Saga and the Poetic Edda preserve the Norse-Icelandic form of this legend; the German Nibelungenlied recounts substantially the same events under different names (Sigurd as Siegfried, Brynhild as Brünnhilde, Atli as Etzel/Attila), reflecting a shared Germanic legendary tradition rather than a single fixed text.