use a master ball on it
Mewtwo, yes, if you have a FireRed or LeafGreen with Mewtwo.
Yes it is in a cave.
To catch Mewtwo in LeafGreen or FireRed no. To migrate Mewtwo from LeafGreen or FireRed to Diamond/Pearl/Platinum yes you have to have it in Diamond/Pearl/Platinum.
u cant get mewtwo in platinum. But, you can get him on: Firered, Leafgreen, ect.
kabamba
use a pokeball and capture professor oak then sack him, then he gives you a mewtwo
Capture him in firered or leafgreen and trade it.
Mewtwo.
Mewtwo!
Mewtwo is found in cerulean cave.
You cannot 'finish' Pokemon LeafGreen and FireRed. You might be thinking about defeating the Elite Four. That is the end point of most trainers, but you can go ahead and capture legendary Pokemon like Mewtwo, Lugia and so-on.
no, firered or leafgreen
Mewtwo, yes, if you have a FireRed or LeafGreen with Mewtwo.
Catch 'em all
No migrate him from firered or leafgreen to get him.
Yes it is in a cave.
He is at the end of cerulean cave.