You have to evolve a Jigglypuff using a moon stone.
you cant but you can find jigglypuff around route 14
Catch a Jigglypuff in trophy garden and evolve it.
Piplup does not exist in Pokemon LeafGreen or FireRed.
No, you cannot find cyndaquil in LeafGreen.
you should go to gamestop
LeafGreen version does not have Growlithe.
In the grass...
You cannot catch houndour in Pokemon leafgreen either get one from Pokemon emerald or Pokemon colosseum.
there is no such Pokemon
That item doesn't exist in leafgreen.
you can't catch aipom in leafgreen but you can get one from Pokemon colosseum or Pokemon emerald.
There aren't growlithe in LeafGreen. FireRed has growlithe, LeafGreen has vulpix.