A Nidhogg can cross your path in "The Witcher Adventure Game". This creature is very hard to defeat and one of the strongest opponents in the game (level: Gold).
To defeat it you need:
Successful Sword: Receive 3 VP. Failed Shield: Suffer 1 Heart for each shield you are short.
- The Nidhogg monster was originally planned as part of the RPG The Witcher 3: Wild Hunt. Geralt should be imprisoned by Yennefer on a small Skellige island called Isle of Trials. Either you could escape by taking the eponymous trials of the island, or you could face off against a monster called Nidhogg. Neither this additional story part/quest nor the monster or even the isle has made it into the final game.