Obtainable from the LCP.
Feeding on the rotting dead, Nidhogg grows in the underworld. Sucking blood, gnawing on bones, it greedily consumes anything it comes across.
In Norse mythology, Níðhöggr (Malice Striker, often anglicized to Nidhogg) is a dragon who gnaws at a root of the World Tree, Yggdrasill. In the mythology, the Nidhogg is said to be controlled by only one person, the Norse goddess named Hel.