Beth Ditto

In Pokémon Red and Blue, Ditto can be found along Routes 13, 14, 15, and 23, as well as inside Cerulean Cave. In Pokémon Yellow, it is available only in the latter location, as well as inside the Pokémon Mansion on Cinnabar Island. In the remakes Pokémon FireRed and LeafGreen, the Pokémon is present in all the listed locations.