I am including this one because of the Norse Mythology about Loki.
Jormungandr is Loki’s middle child with the jotun Angrboda. Odin tossed him into the ocean, where he grew so huge that he encircled the entirety of Midgard. Thor once caught him while fishing with an ox head as bait. According to the Poetic Eddas, Jormungandr is fated to poison the sky with his venom during Ragnarok, the end of the world in Norse myth. This version of him is based on the European adder, one of the few venomous snakes native to Scandinavia.