Monster King Orochi

Orochi looms as a giant, red-skinned figure with luminous yellow eyes set in black, pupil-less sclera. Spiked tentacles jut above his head, rows of fangs crowd his mouth, and serpentine creatures make up his shoulders, wrists, and clawed fingers, while grinning skulls cap his knees beneath a heavy cape and a long barbed tail.

His frame is in truth a seething mass of smaller monsters packed together like muscle. When he cuts loose, he unspools into a nest of writhing dragon heads and claws, and stripping away his mask reveals a centipede-like true shape: a dark, round face ringed with tentacles atop long, powerful limbs that carry him.

Stern and pitiless, Orochi commands hundreds of monsters through sheer presence and rarely speaks, since his creator Psykos, hidden as Gyoro Gyoro, handled the talking and the ruling for him. Years of her brainwashing left him almost wholly obedient, yet he could defy her when it suited him, and he secretly concealed his real strength while using her sacrifices to grow. He is far cannier than his beastly look suggests, praised by Psykos as a fighting genius and among the rare few, alongside Boros and Carnage Kabuto, who sensed Saitama's danger at a glance.

Though a monster, he shows selective restraint, sparing and recruiting figures like Gouketsu and Garou, but he has no tolerance for failure, devouring Awakened Cockroach for losing to Genos. He came to believe an ancient tablet named him the sacrifice needed to be reborn as a god, and after his ruin he fixated single-mindedly on absorbing others and taking revenge on Saitama.

Once a hollowed-out human in Q-City, Orochi was chosen by Psykos and remade through fusion experiments and countless monster sacrifices into the ultimate Mysterious Being and figurehead of the Monster Association. Gouketsu called him the strongest monster alive, and even Metal Knight regarded him warily. He crushed Garou in his half-monster state, copying the Water Stream Rock Smashing Fist after a single look, before Saitama arrived and tore him apart despite his fire breath, shapeshifting, and the Earth-draining Gaia Cannon.

Surviving as scattered gore, he regenerated from his heart by absorbing other monsters, then turned on his own maker Psykos. She resisted total assimilation, and the two merged into a single dragon-headed being empowered further by "God," strong enough to push even Tatsumaki. In the end Tatsumaki shredded the fused body and destroyed his heart, killing him, and his remains were later spent to revive Sage Centipede.