There is only two ways to obtain Mew in Pokemon Fire red.
1. Use a cheatcode
2. Trade Mew from the Pokemon game called Emerald.
You can't..........................Mew does exist in the pokedex but it isn't there in the game......hope this helps
I don't think you can get Mew in Pokemon FireRed at all. You have to trade a Mew from Emerald. You can go to http://www.serebii.net/pokedex-rs/151.shtml to see what I mean.
There is no Mew in FireRed or LeafGreen.
The tanoby key, and the tanoby ruins in island seven. and of course completing the pokedex!
There no Mew in firered.
You must capture Mew on Emerald and trade it to FireRed.
Mew is #151 in the national pokedex, and it is a Psychic type Pokemon.
number 151 in the sinnoh pokedex is Manaphy. Number 151 in the national pokedex is mew.
Mew and mewtwo are part of the kanto pokedex not the hoenn pokedex but you do need these two to finish the entire pokedex.
You can't get mew in firered or leafgreen.
in cereilen cave
mew