What is the rarest pokemon in pokemon go?

The rarest Pokémon in Pokémon Go is considered to be the region-exclusive Pokémon that can only be found in certain parts of the world. Some examples of region-exclusive Pokémon include Kangaskhan (found in Australia), Mr. Mime (found in Europe), Tauros (found in North America), and Farfetch'd (found in Asia).

Aside from region-exclusive Pokémon, some rare Pokémon that are difficult to find and capture include Unown, Shiny Pokémon variants, certain legendary Pokémon like Mewtwo and Rayquaza, and some Pokémon with extremely low spawn rates, such as Gible and Axew.

Players often have to travel long distances or attend special events to have a chance at encountering and capturing these rare Pokémon in Pokémon Go.