In Liptoo Chamber.
Mewto is in a cave that's guarded by that man. you can't go in until you beat the elite four and get all your badges. The cave is in that city or town who's name starts with a C. sorry.
There is no such thing in Pokemon G/S/C.
you get mewtwo in the cave next to cerulean c:
Uuuuuuummmmmmmmmm..........., you don't. C Dawg
You can enter cerulean (It's spelled C-e-r-u-l-e-a-n) cave by winning the Pokemon league. You can find a mystery Pokemon there! (HINT:The mystery Pokemon starts with an M!!)
get the unknown letters R,O,C,K. It'll tell you what letters the stones are in your inventory.
get all 8 gym badges and surf to route 223 and youll c a waterfall . use waterfall and youll c a cave go through the cave and youll c a building go in and there it is . TO C A GUIDE TYPE IN HOW TO BEAT THE POKEMON LEAGE.
26+ the 2 u find after u catch all 26 The 26 arre all the alphabet unknown and the 2 others are the exclaimation point and question mark unknown. On the other side of Veilstone City, there is another cave go in it an a guy wants to race u to c if you can catch all of the unknown faster than he can build a tunnel, so when you catch the alphabet unknown you talk to him and he takes you to the other 2 unknowns. I think you have to have a heart scale though but im not sure.
You must trade it from FireRed or LeafGreen, or have it traded from Pokemon Colosseum or Pokemon XD. In Pokemon C., it would have already been traded from a FireRed or LeafGreen. In Pokemon XD, you can catch it in Phenac City.
juup and spin aror
You can't really get Deoxys in Pokemon Ruby and Sapphire the only way to get it into your game is to transfer it from Firered and Leafgreen and Deoxys is located in Birth Island in Firered and Leafgreen.
yes i have tried it, but it did not work. it may be a miscaculation in if ethier the c unknown was a o. but i will try again. u get a unknow in the seven island at the ruins/.