Midgardsormr

Midgardsormr is one of the Five Great Dragon Kings. Known as the Sleeping Dragon and the Dragon of the End, he is the largest Dragon in existence, with Great Red being second in terms of size. He is also the second child of Loki and the younger brother of Fenrir.

Appearance
A grey Eastern Dragon with an enormous body measuring around 500-600 meters in length, well over five times the length of Great Red's body.

Personality
He is an extremely lazy Dragon, spending most of his time asleep. He is also quite dismissive towards others including his father and brother, claiming that they are meaningless existences to him. When conversing with people Midgardsormr speaks with a well-mannered, very laid-back tone of voice, occasionally falling asleep in mid-conversation.

Interestingly enough, however, is that Midgardsormr doesn't seem to mind waking up when there is something interesting going on, even going as far as saying to wake him up again if something happens.

History
Midgardsormr is the middle child of the Giantess Angrboða and the God Loki. Eventually, Midgardsormr grew so large that he was able to surround the earth and grasp his own tail. When he lets go, the world will end, earning him the nickname "Dragon of the End". Though immensely powerful, his colossal size and laziness left Asgard scratching their heads and they decided to have him sleep at the bottom of the ocean until Ragnarok, thus earning him the second nickname "Sleeping Dragon". In spite of this, he has been known to surface on occasions (though he was still asleep when this happened). During one of these instances, he was taken care of by the local Dark-Elves and Dwarves.

Birth of the Breast Dragon Emperor
Midgardsormr was mentioned in Volume 4 when Ddraig explains to Issei about Ophis and the Five Great Dragon Kings.

The Heroic Oppai Dragon
At the beginning of the Heroic Oppai Dragon arc, the sleeping Midgardsormr is summoned by the Occult Research Club and Vali Team through the Dragon Gate to ask for advice in preparation for their battle against Loki and Fenrir, telling them the method to temporarily capture Fenrir and how to defeat Loki.

Powers & Abilities
Immense Strength: Midgardsormr is a powerful Dragon King, mainly due to his massive size.

Dragon Flames: Midgardsormr also has the ability to breathe Dragon Flames as his clone was able to use that ability.

Trivia

 * Loki (Midgardsormr's father) created at least 10 smaller, mass-produced versions of him.
 * Midgardsormr's name comes from the Old Norse word for the modern name Jörmungandr.
 * In the Old Norse language, Midgardsormr means "Midgard Serpent".