with hax
You can catch Mewtwo at the Unknown Dungeon after beating the Elite Four and entering the Hall of Fame.
go get mewtwo, the legendary dogs go to 1,2,3,4,5,6,7 island and have fun
go to cerulean cave and catch mewtwo
You go to the Cerulean Cave after beating all eight Kanto gym leaders.
after beating elite four go to shinou city then go left talk to two team rocket club members behind them is mewtwo!!!!!!!!!!!
The only area that becomes accessible after defeating the Elite 4 is the Unknown Dungeon (Cerulean Cave), where Mewtwo can be found.
You can go back to Cerulean cave and catch Mewtwo, or simply try to "Catch 'em all"
No, you do not have to catch all the Pokemon to encounter Mewtwo. Mewtwo can be found in Unknown Dungeon/Cerulean Cave in the first Generation games at the deepest part of the cave after beating the Elite Four and the Champion of Kanto.
Mewtwo is good for beating the elite four (2nd turn), since it can learn moves like Flamethrower, Thunderbolt, Ghost Ball, Phsycic. All these moves are good since they're all special attacks and Mewtwo is one of the best Pokemon in sp.atk. These moves are also super effective versus almost everyone in the elite four and this enables you to beat the elite four fairly easy the 2nd time.
the two?? umm do you mean "mewtwo"? well if you do, you get him curclean cave after beating elite four and saving the ice elite four person in an ice cave in one of the sevii islands. if that's not what you meant, well sorry.
The game does open after beating the Elite Four. You simply select Continue, and you will be back at your house after you have beaten the Elite Four and Champion. :3
well you have to wait all credits