In Norse mythology Midgårdsormen (the Midgard Serpent,
or Jörmungandr) was one of the three children of the
giantess Angrboða and the god Loki. The two others were
Fenrisúlfr (the wolf) and Hel. Midgårdsormen lived in the great
ocean that encircles Midgard - biting in his own tail he then
surround the Earth.
The serpent's arch enemy was the god Thor. They had
several encounters but the last meeting between
Midgårdsormen and Thor occured at Ragnarok, when
the serpent came out of the ocean and poisoned the sky.
Thor killed him and then falled dead,
having been poisoned by the serpent's venom
'Hymir rushed forward and cut through the line'
by Arthur Rackham, 1901
The final battle between Thor and the Midgard Serpent during Ragnarok
by Lorenz Frølich (1820–1908), 1895
Emil Doepler (1855-1922): 'Thor und die Midgardsschlange'.
A scene from Ragnarök, the final battle between
Thor and the Midgard serpent, 1905
the Midgard Serpent
from the 17th century Icelandic manuscript
'The children of Loki' by Willy Pogany, 1920
Johann Heinrich Füssli:
'Thor fighting the Midgard Serpent', 1788