Orochi

"Monster King" Orochi ("怪人王"オロチ, Kaijū-ō Orochi) is a high-ranked Mysterious Being of the Monster Association.

Appearance
Orochi is a large and ominous-looking monster. He has several large spikes pointing upwards above his head, cracked skin, empty eyes, and a multiple set of pointy teeth inside his mouth. His shoulders, wrists and fingers have the appearance of monstrous snakes' heads with pointy teeth, with the latter ending in large claws. His knees have the appearance of snake skulls and his clothing consists of a large cape connected to a circular, veiny joint in the center of his chest and a piece of cloth covering his lap.

Monster Association Arc
Gyoro Gyoro is speaking with Orochi about the monster raid's situation.

After Tatsumaki killed the Hundred-Eyes Octopus, Gyoro Gyoro finds the situation troublesome, but Orochi sees it as not a concern because they can make as many Mysterious Beings as they please.

Through his robot Bofoi questions Orochi and Gyoro Gyoro about their goals and while they tell him destruction is a natural part of a monster's instincts, but it is not their end goal.

Abilities and Powers
Due to his large stature and his epithet as the "Monster King", it could be assumed that he is one of the strongest monsters in the Monster Association. Gyoro Gyoro also stated that Orochi is above all of the Monster Association's main forces.

Monster Creation: While it has yet to be seen Orochi apparently the ability to create as many of mysterious beings as he wants.

Trivia

 * The name "Orochi" (大蛇) literally means "great snake".
 * Orochi is the sixth of many "Kings" mentioned in the series, the others being the Subterranean King, the Beast King, the Deep Sea King, the Ancient King (anime-only), the Sky King, and the Forest King.
 * He is the only king with a confirmed name.