 "There are many stories of "kynjaskepnur", that is, strange animals or unknown phenomena, in Lagarfljót".These include accounts of the Lagarfljót Worm, as well as other monsters, a "strandvorm", or a monstrous seal or poisonous skate.The legend of the worm is arguably first mentioned in the entry for year 1345 in Icelandic Annals (specifically the "Skálholts Annáll" which reaches AD 1430), although the text only refers to the sighting as a "wonderful thing" () or a marvel, and not specifically as a worm.