
1) MacOS game 2) PlayStation Network game 3) Windows game
Found on
https://www.crosswordclues.com/clue/nidhogg
[video game] Nidhogg is a side-scrolling two-player fighting game by Mark `Messhof` Essen. Players duel with swords in a pixelated environment. The game was commissioned for the New York University Game Center`s annual multiplayer show, and was revised and demoed at private events over the next four years before its final release. It won In...
Found on
http://en.wikipedia.org/wiki/Nidhogg_(video_game)

(from the article `Hel`) ...the shore of corpses. There stood a castle facing north; it was filled with the venom of serpents, in which murderers, adulterers, and perjurers ... ...third into Asgard, home of the gods. At its base were three wells: Urdarbrunnr (Well of Fate), from which the tree was watered by the Norns (the ... [2 rel...
Found on
http://www.britannica.com/eb/a-z/n/40

In Norse mythology, Nidhogg is a dragon which devours the corpses of evil doers. He lives in Hwergelmir, in the realm of Hel.
Found on
http://www.probertencyclopaedia.com/browse/D4.HTM

a serpent in Niflheim who gnaws upon the lowermost root of Yggdrasil.
Found on
https://www.infoplease.com/dictionary/nidhogg
No exact match found.