Níðhöggr

Níðhöggr (Old Norse: Níðhǫggr, [ˈniːðˌhɔɡːz̠], lit.'Níð-Hewer', "Malice Biter/Striker"?), often anglicized Nidhogg, is a Germanic dragon in Norse mythology who is said to gnaw at the roots of the world tree, Yggdrasil, and is likewise associated with the dead in Hel and Niflheim.