Luigi

Luigi is the brother of Mario and is the most rumored character in Super Mario 64. Countless theories on how to unlock him were created all proven false because he is not even in the game's code although he is referenced in the game's source code. He was in the game early in a scrapped multiplayer mode but it was taken out because the game would have to have simple level design. Luigi has been rumored to be in the 1995/07/29 Build. People thought the star in the yard had a connection with Luigi. However Luigi's presence seems to be false in the current state of the game that is accessible without serious modding of the game's files or access to Big Chungus.