Níðhöggr or Nidhogg (Malice Striker) is a powerful dragon that is found in Norse Mythology. The mighty dragon chews on the roots of the ash tree Yggdrasill, also known as the World Tree, which holdes the 9 realms of Norse mythology together. He hopes one day to topple Yggdrasill and destroy all realms. He has a rivalry with an eagle that lives at the top of the World Tree and the two exchange harsh words through Ratatöskr, the squirrel, that bears the words between the two. It is said that the Níðhöggr will arrive at Ragnarok, the Norse Judgement day.
In the computer video game Age of Mythology, worshipping the Norse deity Hel rewards you with the ability to summon the Nidhogg dragon, one of the three flying units in the game, the others being the Phoenix and the Roc.
In the video game, Lord of Arcana, Nidhogg is the first and second last boss creature, and resembles a winged dragon.
an illustration from a 17th century Icelandic manuscript of the mighty Nidhogg gnawing at the roots of Yggdrasill