As a Pokémon expert, I can tell you that Porygon's evolution process is a bit different depending on which game you're referring to. In the main series games, Porygon evolves into Porygon2 when traded, and then Porygon2 evolves into Porygon-Z when traded while holding a Dubious Disc.

However, if you're asking about a specific game called "Moon" which is not a part of the official Pokémon series, I cannot provide an accurate answer as it is not recognized within the official Pokémon universe. The Pokémon Company has not released a game with the title "Moon" that would be relevant to Porygon's evolution.

If you meant the Pokémon Sun and Moon games, Porygon still evolves into Porygon2 when traded, and then into Porygon-Z when traded holding a Dubious Disc, just like in the other main series games.

read more >>

Obtain a Dubious Disc. You will need to give this item to Porygon2 to hold. When Porygon2 is traded while holding a Dubious Disc, it will evolve into Porygon-Z. You can get a Dubious Disc in Gen 4 (Diamond, Pearl, and Platinum) and later.read more >>