Nibelungs (or Nibelungen), in Germanic and Scandinavian mythology, a race of dwarfs or elves dwelling in Niflheim (or Nibelheim), a realm of mist or darkness. According to some accounts, the Nibelungs were the descendants of Nibelung, a legendary Scandinavian king, and heirs to a vast treasure hoard of gold and jewels that had been amassed in some ancient time. Because of its origins, the treasure never ceased to be tainted with corrupting greed and madness. There are conflicting accounts and treatments of the Nibelungs in the various sources. Nibelungs were sometimes referred to as Niflungs, and the treasure, called the Rhine gold, was said to be guarded by the dwarf Andvari (or Alberich). In the 'Volsunga Saga', the hero Sigurd acquires the gold by slaying Fafnir, who had killed his own father, Hreidmar, for it and turned himself into a dragon to protect it. Also in the 'Volsunga Saga', Nibelung was the son of Hogni and grandson of Giuki. In the Germanic 'Song of the Nibelungs' (Nibelungenlied), the term is used in the latter part of the epic as an alternative name for the Burgundians. The Burgundians came into possession of the treasure hoard through Siegfried (Sigurd), who had married the Burgundian Kriemhild (Gudrun). In the 'Song of the Nibelungs', Siegfried had already won the gold by defeating the dragon Fafnir and his brother Regin before the narrative begins. In the 'Poetic (or Elder) Edda', the Nibelungs were the kinsmen of Giuki, whose daughter Gudrun had married Sigurd. In Richard Wagner's operatic cycle 'The Ring of the Nibelungs', the Nibelungs were gnomes, dwarfs, or elves, such as Mime (a parallel of the Regin character) and Alberich, who had put his curse on a ring that was part of the treasure when the hoard was stolen from him by the gods.