Shedinja

Shedinja (Japanese: ヌケニン Nukenin) is a dual-type Bug/Ghost Pokémon introduced in Generation III.

It is considered a special evolution of Nincada, appearing only when Nincada evolves into Ninjask starting at level 20, as long as there is an extra space in the player's party and an extra Poké Ball in the player's bag. An extra Poké Ball is not necessary to obtain Shedinja in Generation III.