The only way you can get to one island is with either a tri-pass or a rainbow pass (you get the rainbow pass after you beat the elite four as well as the tri-pass if you didn't already have it) but as soon as you do you go to Vermilion city and you are able to pick from islands one to three with the tri-pass but with the rainbow pass you can pick from one to seven islands! As long as you've been on the boat before to get something from someone. Just never mind that.
he isn't in the one island
You get Squirtle as one of the starter pokemon.
One island in the north.
After fixing the Network Machine on One Island, you can trade a Mudkip from Pokemon Ruby or Sapphire. You can't catch a Mudkip in Pokemon FireRed.
Hoothoot is normally unavailble in firered you will need to have emerald version trade you one or you can get one from colosseum.
use that gameshark user.
he isn't in the one island
you can't they only put that in on the remakes of the game (firered and leafgreen)
You get Squirtle as one of the starter pokemon.
he is in one island in the hospital.
Give it to Celio on one island.
One island in the north.
You get a map from Celio, on one island.
Vulpix is an exclusive pokemon to Leafgreen version if you trade one from Leafgreen to Firered you will be able to have it.
no but you can trade to firered and leafgreen for one
If you mean Celio, his in one island pokemon center.
it's on island one after you talk to the guy about the gem the two guies at the mountain they open a hole enter and it's in the cave.