Mimikyu

Sun: Its actual appearance is unknown. A scholar who saw what was under its rag was overwhelmed by terror and died from the shock.

Moon: A lonely Pokémon, it conceals its terrifying appearance beneath an old rag so it can get closer to people and other Pokémon.

Ultra Sun: Although it’s a quiet, lonely Pokémon, if you try to look at what’s under its rag, it will become agitated and resist violently.

Ultra Moon: A gust of wind revealed what hides under this Pokémon’s rag to a passing Trainer, who went home and died painfully that very night.

Sword: It wears a rag fashioned into a Pikachu costume in an effort to look less scary. Unfortunately, the costume only makes it creepier.

Shield: There was a scientist who peeked under Mimikyu’s old rag in the name of research. The scientist died of a mysterious disease.