I heard that you could encounter 'M in Ru/Sa and I wondered what was the code to do that, besides I think that why would the programmers stuff him in the game after 9 years of hearing the same glitch?! I REALLY REALLY want to see the 'M in my Ruby. Wonder what it would look with the nicer graphics of Ru/Sa? O_o
first of all, you are posting in the wrong section, but i will answer your question. first, find your rival when you are not supposed to battle her/him. save your game, then talk to him/her. right when s/he is saying the last sentence, shut the game off. turn it back on, and go to shoal cave in mossdeep city. save your game before you enter, then enter. but quickly before you see shoal cave, in that second when where the screen is all black, shut the game off. turn it back on, and you should see yourself in the middle of the entrance. press the a button, and 'M will appear. it will be recorded as #000, but be careful, if you do catch it, then all of your pokedex data will disappear. it's never worked for me, just to let you know.