Stoor worm
The stoor worm, or Mester Stoor Worm, was a gigantic evil sea serpent of Orcadian folklore, capable of contaminating plants and destroying animals and humans with its putrid breath. It is probably an Orkney variant of the Norse Jörmungandr, also known as the Midgard Serpent, or world serpent, and has been described as a sea dragon.