help if you know!!!!!!!

it's quite simple really. just beat the Elite Four, then Fly back to Cerulean. Surf to the cave there, and you'll find Mewtwo in there. I do suggest using the Master Ball to catch Mewtwo, but it is possible to get it with an Ultra Ball if you're good. (a Great Ball if you're awesome, a Poke Ball if you're a cheat)

I used great balls to capture Mewtwo - don't bother using a master ball.

I think I froze it with Articuno, put it down to little life with the rest of my pokemon, put it to sleep with Haunter and threw I think 8 great balls at it.

The cave's north of the city...go up past all those guys up the narrow path, and surf down the water to your left.

The caves hard to navigate if I remember right.

ok cause i havent been able to

Seriosly? I thought that Mewtwo was a glitch pokemon like mew.

1. paralyze, sleep, or freeze Mewtwo
2. throw ultra balls