Nidhogg

In Norse mythology, Níðhöggr (or Nidhogg) is a fearsome dragon or serpent that resides in Niflheim, the world of the dead. Niflheim is a cold, dark, and misty realm situated beneath one of the roots of the world tree, Yggdrasill. Níðhöggr's primary role is to gnaw at the roots of Yggdrasill, constantly threatening the stability of the entire world. This dragon also dwells on Nastrond, the Shore of Corpses, where it consumes the dead and, in some accounts, sucks the blood from their bodies. Níðhöggr is often depicted as bickering with an eagle that sits atop Yggdrasill, and it is aided by other serpents in its destructive efforts.123