First, you will need to win a Porygon at the Celadon Game Corner. Then at Silph Co. you will receive the Up-Grade from a guard (sorry I can't be more specific). Give it to Porygon, and trade it. Now you have Porygon2. Next you will need the Dubious Disk, which is found using the eastern entrance of Mt. Mortar and requires Rock Climb. Give that to Poryogn2 and trade it to receive a Porygon-Z.
Porygon-Z is a Normal type pokemon.
porygon z is at the oil field hideout
It evolves Porygon into Porygonz.
the upgrade is used to evolve porygon into porygon-z
You can find and win an unlimitd amount of Porygon in the Celadon Game Center.
Porygon-Z is #474 in the national pokedex, and it is a Normal type Pokemon.
you can't. dubious disc is to evolve porygon 2 into porygon z, porygon z is a sinnoh Pokemon and leaf green only goes up to hoeen
Porygon-Z can breed with Porygon and Porygon2 (its earlier evolutions) when both are of opposite genders. However, Porygon-Z cannot breed with other Pokémon outside its evolutionary line.
Porygon-Z
You must win it at the Celadon City Game Corner.
plaay the coin game and save up your coins
It evolves Porygon 2 into Porygon-Z when you trade Porygon 2 while it is holding the Dubious Disc.