In The Saga of the Volsungs, the cursed ring sought by Andvari is called Andvaranaut.
Andvaranaut belongs to the treasure of Andvari, a dwarf or shape-shifting figure whose gold becomes central to the Volsung story. After Loki captures Andvari, the dwarf is forced to surrender his wealth, including the ring. Andvari places a curse on the treasure, declaring that it will bring death to whoever owns it.
The ring passes through several important hands, helping connect the tale of the Volsungs with the wider Germanic tradition of the cursed hoard. Sigurd eventually acquires the treasure after defeating the dragon Fáfnir, who had taken the hoard from his father, Hreiðmarr. The ring’s destructive history resembles the better-known ring curse in Wagner’s Ring cycle, although the names and details differ.
Andvaranaut is often confused with Draupnir, Odin’s self-multiplying ring in Norse mythology. Brísingamen is also unrelated: it is the necklace associated with the goddess Freyja.