You have to trade it in from another game.
Seafoam islands
Psyduck is only in firered trade one to leafgreen.
You can get psyduck by throwing a poke ball at him that will let you have him.
Chat with our AI personalities
Psyduck is in firered not leafgreen you can find it using a good or super rod in the safari zone.
The safari zone.
some Kanto city in the water i think. But for sure in the water in the Safari Zone. ANSWER : Psyduck cannot be found in Leaf Green, only in Fire Red.
in leaf green you cant find ekans, arbok, oddish, gloom, vileplume, psyduck, golduck, growlithe, arcanine, shellder, cloyster, scyther, and electobuzz but you can trade them from fire red.
Psyduck evolves into Golduck, starting at level 33.