make sure you have surf and fly and have been to cinnabar.put the item you want in 6th place.then fly to viridian and talk to the old man that was collapsed at the start of the game awnser no,then after he catches a weedle,fly to cinnabar.go to the right until you see the water.then surf up and down beside the island until you run into the glitch pokemon "missingo".even know its a level 136 you can deafeat it easily(or sometimes a level 0 when its name is messed up).after you beat him go back on land and check your chsen item.it should have some crazy picture then a number. note:dont catch missingo or your game will be deleted.