Jörmungandr

Jörmungandr also known as The Midgard Serpent Or World Serpent is a giant Serpent and is one of the Children of Loki, Jörmungandr is Arch-Enemies with Thor the Thunder God, Jörmungandr is Killed by Thor during Ragnarök, Thor also died to it infecting Thor with it's Venom killing Thor after 9 steps after he killed Jörmungandr