in the trainer tower . it is a reward.
Upgrade,which is an item,is an item that when held by a Porygon and is trade the porygon evolves to porygon 2
To evolve Porygon when it holds the item 'upgrade' and it is traded over to another game. It will evolve into Porygon2.
That item doesn't exist in leafgreen.
That item doesn't exist in leafgreen.
Raise to level 20.
No where, as it as Gen 4 item.
That item doesn't exist in leafgreen.
eiquip it to porgon then trade it to get a porgon 2
you will find it on island 7 when you complete the battle tower
give it to a porygon and trade it to another person and it evolves into a porygon2
You need a special item from Nintendo to unlock the item to get to the island where you can catch it.
you cannot buy this item