Nyan

Standing upright on a cat's frame, Nyan is covered in pale fur marked by dark banding that runs along its spine and tail. A trio of vertical lines streaks over its skull from brow to nape, and a collar with a small bell hangs at its neck.

Boastful and sure of its own power, Nyan nonetheless picks its fights, striking only when the odds or a surprise favor it. The moment Saitama proved untouchable, it bolted rather than die, exposing the coward beneath the swagger. It relishes drawing out the suffering of weaker heroes, a bully at heart, and lets fellow monsters chase their vendettas freely, since it embraced monsterhood mainly to live by its own rules.

Open displays of affection unnerve it, echoing the smothering love of the owner it once endured, though whether this ever dulls its fighting is unclear. Even in its former life as an ordinary cat it was sadistic, tormenting prey until it died in agony. In the end its overconfidence against Drive Knight, whom it badly underestimated, sealed its defeat.

Nyan began life as a pet whose owner smothered it with unwanted kisses and hugs, before some unknown event turned it into a speaking, intelligent monster that joined the Monster Association. It broke into Smelly Lid Prison, converted the inmates into monsters with Monster Cells, and later coordinated those recruits against the Hero Association. When Puri-Puri Prisoner's loving nature made him too much trouble, Nyan slipped away through cracks in the walls, and after watching Saitama flatten Overgrown Rover, it fled him in terror once its Super Feline Retribution did nothing.

Its rampage against a group of A-Class heroes ended when Drive Knight intervened. By constantly shifting forms and flooding Nyan with fire once it crept inside his body, the hero burned, stabbed, and captured it, admitting he only won thanks to data gathered from its earlier fights and its own arrogance. Nyan is later locked in an iron restraint to be dissected. Its strength came from razor claws that could rend S-Class skin, swipes that hurl building-cutting shockwaves, speed enough to deflect a sniper round, and an elastic body that squeezes through gaps only millimeters wide.