In Norse mythology, the water serpent said to encircle the Earth is known as Jörmungandr, or the Midgard Serpent. According to myths, Jörmungandr was so large that he could grasp his own tail, symbolizing the interconnectedness of the world and the cycle of life. He represents chaos and the challenges of existence, playing a significant role in the eventual conflict of Ragnarök, when he faces off against the god Thor. His presence contributes to the rich tapestry of Norse cosmology.