Quoted By:
if you beat the elite 4 50 times in a row with mewtwo without losing and then talk to professor oak 256 times he tells you about a rare pokémon seen in cerulean cave and if you go there you can catch one of the clone starters, the one weaker than the one you picked at the beginning, and it's stronger than the normal ones. i havent tried this on yellow cause it's at my dad's house but maybe you get pikachu on that one
