go to the moon cave first then go down some stairs where all the wild Pokemon are paras
teach a Pokemon thief so you can steal there mushrooms
you are more likely to get a tiny mushroom rather than big mushroom
if you use thief and you get nothing don't bother agagain because that Pokemon isn't carrying anything
oh and thief still works if you make the Pokemon faint :]
The Big and Small mushrooms are for selling they can get you some money.
You can't find a Vulpix in Pokemon FireRed version. That pokemon is version-exclusive to Pokemon LeafGreen.
You can only find Skarmory in the Pokemon SoulSilver version.
In Pokemon Crystal Version, a Heracross will occasionally appear when you use headbutt on trees.
after beating the game, insert the Pokemon leafgreen version for gameboy advanced in the GBA slot. You can then catch Pokemon from that version.
The Big and Small mushrooms are for selling they can get you some money.
on paras
Pokemon ruby's version IS Pokemon ruby.
route 14
You can't find a Vulpix in Pokemon FireRed version. That pokemon is version-exclusive to Pokemon LeafGreen.
You can give her tiny mushrooms or big mushrooms.
Pokemon crystel version
When you first go to the Ecruteak Poke-Center you will find him. Then you can find him in a small house in Goldenrod City, he will give you an Evee.
You can't find Articuno in pokemondiamond but you can migrate it in pokemon leaf green version or pokemon fire red version.
you cant, though you can find tiny mushrooms and mushrooms as items in the game... if you took those mushrooms in the game, it might just be possible
a paras or parasect might be holding one
there isn't one you just sell the mushrooms