Its in cerulean cave but you need all kanto badges before you can go in just like in the old school games
Can You Get Mewtwo In Pokemon Silver Version?
Yes you can go to the cave by misty gym and look around and you will find it it will be visible
Yes you have to get all the badges and beat the elite four then go to the cerulean cave take a lot of repels because its quite long also I caught mew so I had both of them
I'm not sure you can without action replay srry but maybe theres a way I'm not sure srry don't waste your time trying to do what that other guy said.
I did and I didnt find him or it what ever it is
Yes you can first go to pallet town and talk to everyone after you do that you go to route 4 and walk around at night time and in the grass and after a while you will find it.