1. Get a Red and a Blue Version, and a Dratini in one of them.
2. Trade the Dratini to the other version.
3. Evolve the Dratini into a Dragonair.
4. Now trade it back.
5. Evolve it again into a Dragonite.
6. Now trade it over again.
7. With it either in the first or last place in your party (I can't remember), go to the exact spot where Mewtwo was standing in Cerulean Cave.
8. Use a Moon Stone on it, or some certain stone (I forget which one.)
Anyone who still plays Halo PC (not CE) can join my server titled:
MASS CTF WAR MODDED (i7 server)
My username's Ultrafrigid. It's not a dedicated server, so it won't always be up.