I dont think you can.
Chat with our AI personalities
just run in the grass
That item doesn't exist in leafgreen.
Piplup does not exist in Pokemon LeafGreen or FireRed.
Psyduck is in firered not leafgreen you can find it using a good or super rod in the safari zone.
you find chinchou under the sea when you diveChinchou cannot be obtained in LeafGreen you will need to trade it from Emerald.