Porygon2

Porygon2 is a Normal-type Pokémon from Johto region. It evolves from Porygon when fed with 50 candies and Up-Grade is used.

Trivia

 * Like other Pokémon that require an evolution item to evolve into them, Porygon2 doesn't spawn in the wild nor hatch from eggs and only way to acquire it is by an evolution.
 * Since Generation IV of core series games, Porygon2 evolves into Porygon-Z, but in Pokémon GO it's currently not possible.