No, there isn't, just different pictures.
there is no difference between attacks or hp or ANYTHING like that... just the picture (reason i know: i have them both)
Mewtwo is at level 70 when you find it on leaf green.
Snorlax,Charizard,Flygon,Raichu,Lucario,Infernape,Electivire,Porygon Z,Torterra,Empoleon,Mewtwo
he is level 70
Mewtwo is at Level 70 when you battle him. You should most likely use you highest level Pokemon that is around level 70.
Mewtwo learns Aura Sphere at level 93.
70
70
Mewtwo doesn't learn Psybeam.
You find him at level 70.
No. The only Mewtwo found in Kanto dwells in Cerulean Cave, and is at Level 70.
Lv70