A lonely Pokémon, it conceals its terrifying appearance beneath an old rag so it can get closer to people and other Pokémon.
– Pokémon Moon Pokédex
When I first saw Mimikyu’s design in a Corocoro magazine scan, I was skeptical about it, but after reading its story, I felt bad for it. Even its Pokedex entry is sad.
Nobody has seen what’s under the rag. The Sun Pokedex entry says a scholar who once saw it died from the shock. Like what’s underneath a Diglett, what’s under a Mimikyu’s rag will forever be a mystery. When its disguise is broken, it’s considered another form (I like the sound effect of Mimikyu’s disguise being broken).
Despite being a Pokemon that doesn’t evolve, it is pretty useful competitively. Its ability Disguise gives a free turn to set up. It has good defenses, decent attack and speed, and learns useful coverage moves.
Mimikyu is the only Ghost/Fairy Pokemon.
In the anime, Jessie has a Mimikyu. It mostly joined Team Rocket because of its grudge against Pikachu, and often will only fight if Pikachu is involved in the fight.