Odin cast Jörmungandr into the deep sea that encircles all the land. There the serpent has grown so large that it encircles all Midgard and bites its own tail.
Jörmungandr, þat er Miðgarðsormr, kastaði Óðinn í þann djúpa sæ er liggr um alla jörðina. Ok vex sá ormr svá at hann liggr á miðju hafinu ok umlykr alla jörðina ok á hann sjalfr sporðinn í munni sér. Þór mun eiga víg við þenna orm á dómadegi.
The Midgard Serpent, Jörmungandr, was cast by Odin into the deep sea that lies around all the earth. The serpent has grown in those deep waters and encircles all of Midgard, holding its own tail in its mouth. Thor is fated to meet the serpent in battle on the day of doom.
Eddic quotations
Þá kemr inn mæri mögr Hlöðynjar, gengr Óðins sonr við úlf vega; drepr hann af móði Miðgarðs véurr, ganga níu fet Fjörgynjar burr.
Then comes the glorious son of Hlodyn, the son of Odin goes to fight the wolf; in his fury he slays the guardian of Midgard, nine steps does the son of Fjorgyn stride.