Níðhöggr

Níðhöggr ('Malice Striker') dwells in Náströnd at the shore of the realm of the dead in Hel, where he gnaws the roots of Yggdrasil and chews the corpses of murderers, oath-breakers, and adulterers. He is the great serpent/dragon opponent of the eagle that lives in Yggdrasil's crown, and the squirrel Ratatoskr runs messages of insult between them. At Ragnarök, Níðhöggr flies out carrying corpses on his wings.

A vast serpentine dragon, sometimes described as dark-feathered or scaled, coiled perpetually around the third root of Yggdrasil that extends into Niflheim. He is surrounded by countless smaller serpents also gnawing the World Tree. His wings are enormous, blotting out the sky when he finally rises.

By gnawing Yggdrasil's roots he works toward the dissolution of cosmic order. His presence sustains the realm of the worst dead, where he feeds on corpses. Survives Ragnarök — one of the few beings to do so. His flight at the end of days signals the final defeat of the gods.