Shedinja

Shedinja, known as Nukenin in Japanese, is a dual-type Bug/Ghost Pokémon introduced in Generation III. It is not a typical evolutionary form but rather a byproduct that appears when Nincada evolves into Ninjask at level 20, provided there is an empty slot in the player's party and an extra Poké Ball. Shedinja resembles a cicada's shed exoskeleton, with a light brown body and a gray abdomen. It has four protrusions in place of legs, round protrusions on its head with narrow slits for eyes, and tattered wings revealing a hollow interior. It is said that Shedinja originates from discarded bug shells, and peering into the hole on its back is said to steal one's spirit. Its HP is always 1, and it possesses the unique ability 'Wonder Guard,' making it only vulnerable to super-effective moves. Shedinja cannot be found in the wild and is primarily obtained through the special evolution method.