Jormungand, J ö rmungandr, J ǫ Rmungandr, meaning "giant", is a giant sea snake in Nordic mythology that can surround the human world. It belongs to the giant race and is the second son of the god of cunning, Loki, and the female giant Angelberda, as well as the brother of Finriel and Hera.
Due to its excessive danger, it was thrown into the bottomless depths of the human world of Midgard by Odin. Yemengkad is the strongest among the Giants, hence he is known as the 'Mi' ð Gar ð Sordr, Midgard Serpent). And its arch enemy in life is the strongest among the gods - Thor, the god of thunder.

According to the Icelandic epic 'Ada', Yemengad is an extremely large serpent, filled with evil power along with the giant wolf Finrill and the god of death, Hera.
Lord Odin felt that these three children of Loki were a significant threat to Asgard and would also be the cause of destruction to the world, so he came up with ideas to suppress them. Odin, while still young, threw Yemengjia into the bottomless abyss surrounding the human world, trapped by his own weight and the pressure of the seawater.
The giant snake's body size was already very large. It stretched its body and unexpectedly encountered its tail at the other end of the deep sea. Yemengjia couldn't break free in the sea, so he had to close his body tightly and surround the entire world (Midgard), so he was known as the "mortal python" and the "giant snake surrounding the atrium".

1. A cat that cannot be lifted
Once, Thor, the god of thunder, visited the Kingdom of Giants and met the local king Utja Loki. Utga encountered some difficulties and made Thor difficult, one of which was to ask Thor to lift one of his cats. Thor, known for his immense strength, was put to the test. However, despite trying his best, he could only lift one foot of the cat, which made Thor extremely frustrated. Finally, Utja Loki told Tor that the tests he had been casting along the way were all spells he had cast. The cat he had asked Tor to lift was actually a manifestation of the giant snake Yemengad. The vastness of Yemengarde is enough to surround the human world, and Tor can even lift it up in part, demonstrating how powerful Tor's power is.
2. Tor Fishing for the Giant Snake Yemengkad
Once, Thor accompanied the giant Shimir to sea for fishing. In order to demonstrate his strength to Shimir, Thor drove the ship far offshore and used the head of the giant cow as a bait. He placed it deep in the ocean to attract the giant snake Yemengjia to bite it. After that, he used all his strength and the horn power of the giant snake biting the cow's head to successfully pull the giant snake out of the sea. After rushing to the sea, the giant snake Yameng Gad was both startled and angry, constantly releasing poison gas and snake blood, and using force to pull the cow, wrestling with Tor, and even the ship on which Tor was based was damaged by the giant snake. At this moment, Thor picked up the Thor's Hammer, Mirnier, and wanted to strike the giant snake's head. However, Shimir was so afraid that he cut the silk thread. As a result, the giant snake fell back into the sea, and from then on, Thor formed a grudge against him.
3. The ultimate battle between Thor and the mortal python
In the apocalyptic battle of Nordic mythology, "The Twilight of the Gods," Yemengarde resonated with the evil forces on earth. It woke up from its sleep and kept tumbling on the bottom of the sea, setting off towering waves. It spewed deadly venom and gas from its mouth, polluting the entire ocean, filling the entire universe, and arriving on the land of Asgard, officially declaring war on the gods. Its belligerent opponent is Thor, the Thor who has a deep grudge against it. During the battle, the giant snake kept spraying venom at Thor and using all means to attack him. Thor was deeply aware of the power of the giant snake and dared not neglect it. He threw his weapon, Thor's Hammer Mirnier, three times at the giant snake, but even the Thor's Hammer, which was bound to hit the target, was cleverly avoided by the giant snake. Finally, Thor successfully hit the head of the giant snake with a magic hammer, smashing its head and killing it. However, the venom of the giant snake also penetrated Thor's body, and both sides died together.

In many cultures around the world, there is the image of a snake with its head and tail connected, such as Ouroboros. "Ouroboros" means "a snake biting its own tail". It is head and tail intertwined, hermaphrodite, coiled around the entire world, symbolizing "everything", "perfection", "reincarnation", and "yin and yang", representing the recurring phenomena of nature, which are both the beginning and the end, Therefore, some people also consider it as a symbol of the double faced god Jianas in Roman mythology, as Jianas is in charge of the beginning and end of things.
Dennis Holloway once compared Uloporos to Timous, a subordinate of the underworld god Pluto: "It has no eyes, nor does it need them, because there is nothing in front of it. There is no object or sound around it, and time stops for it. It does not need food, because it neither produces nor consumes, and all actions are caused by it, and nothing can affect it. Interestingly, The 19th-century German chemist Kekuler guessed the structure of the benzene ring only because he dreamed of snakes holding their heads and tails in a dream.