The Lagarfljótsormur, Lagarfljót worm, (or simply Iceland Worm Monster) is an Icelandic lake cryptid which is purported to live in Lagarfljót in Egilsstaðir. Sightings have been logged since 1345 and continue into the 21st century including a 2012 video supposedly showing the creature swimming, and an origin of the creature is given in Jón Árnason's collection of Icelandic folktales and legends published in 1862 and 1864.
