Clear the Mewtwo Bonus Stage more than twice in one game, and go to Indigo Plateau (either table will work.) Activate the three Catch 'em Arrows on the right of the board and enter the Pokemon in the top right of the board to activate Catch 'em Mode. The chance of the Pokemon that appears being Mew is 1 in 16. Note: You cannot catch Mew like a normal Pokémon. Mew will automatically be recorded in the Pokédex if you do not lose your ball during Catch 'Em Mode.