 The stoor worm is likely to be an Orkney variant of the Norse Jörmungandr , or world serpent , also known as the Midgard Serpent . The Orcadian folklorist Marwick highlights the similarity between the method Assipattle used to kill the mythical creature and those recounted in the slaying of the Worm of Linton and the Cnoc na Cnoimh of Sutherland tales . He also notes that in Bel and the Dragon , the dragon is killed by Daniel using " fat and hair " instead of peat . In Shetland there was a long @-@ standing belief that " away , far out to sea , near the edge of the world , lived a monstrous sea @-@ serpent that took about six hours to draw in his breath , and six hours to let it out " , which Marwick speculates was probably an explanation for the cycle of the tides . 
