In Pokemon firered you can't, but in Pokemon leafgreen you can get it then trade it to Pokemon firered.
Pokemon Emerald: Birth Island Pokemon Sapphire: Trade from Pokemon FireRed, LeafGreen, or Emerald. Pokemon Ruby: Trade from Pokemon FireRed, LeafGreen, or Emerald.
You cannot "trade" pokemon between Pokemon FireRed and Pokemon Pearl. Instead, pokemon from Pokemon FireRed Version can be transferred to Pokemon Pearl via Pal Park.
Catch, trade, and battle Pokemon
Trade it from Pokemon Emerald or Pokemon XD.
In Pokemon firered you can't, but in Pokemon leafgreen you can get it then trade it to Pokemon firered.
Trade it with a friend, then trade it back to yours.
Pokemon Emerald: Birth Island Pokemon Sapphire: Trade from Pokemon FireRed, LeafGreen, or Emerald. Pokemon Ruby: Trade from Pokemon FireRed, LeafGreen, or Emerald.
no you can't but you can migrate in into diamond and then trade it.
You cannot "trade" pokemon between Pokemon FireRed and Pokemon Pearl. Instead, pokemon from Pokemon FireRed Version can be transferred to Pokemon Pearl via Pal Park.
Catch, trade, and battle Pokemon
Trade it from Pokemon Emerald or Pokemon XD.
You must trade with Pokemon collesium or Pokemon gold
No you don't have to. But if you want every Pokemon you must.
You will have to trade it from other pokemon.
You trade from Pokemon FireRed/LeafGreen
You have to trade and catch as much Pokemon as you can