Cheatcodes or luck.
You can't get mew in firered or leafgreen.
mew and mew two
mew and mew two
blue mew is a shiny version of mew so you have to be very lucky to catch a shiny Pokemon let alone a shiny mew
There is no Mew 3.
Mewtwo? Plus you cannot get Mew in Leafgreen or Firered.
You can't catch mew on leafgreen you need gameshark codes for that
you can get a shiny Eevee on Pokemon leafgreen but its rare. its about a 1/5000 to get it
Mew two
No.
yes
Mew has to be traded from emerald and ho-oh you have to get from Pokemon colosseum.