Mewtwo

Mewtwo is the most difficult Pokemon to capture. You've heard about it. You've read about it. Now you have to face it. Mewtwo was created in the lab on Cinnibar Island after years of research on DNA and gene splicing. Scientists were able to genetically process the cells of Mew, the rarest Pokemon on Earth, to create the ultimate fighting machine. But they lived to regret it. Mewtwo is fierce and extremely hostile. It can't deal with being in a Poke Ball. So don't even try it. You'll need a Master Ball to capture this ferocious feline. Mewtwo can only be found after you have defeated the Elite Four. It will test every skill you have gained along your journey. If you defeat Mewtwo, you will be worthy of the title The World's Greatest Pokemon Master.