Robo-Mario

Robo-Mario is an unused boss fight from the March 5th 1996 build of Super Mario 64. It was discovered by FANDOM user DannyShellstar. The person who gave DannyShellstar the ROM said that storywise, "the robotics division of the Koopa Troop made it."

Discovery
FANDOM user DannyShellstar was playing a ROM allegedly of a build of Super Mario 64 dated before E3 1996, given by an anonymous user on Skype. He went up to the third floor, and found an entity identical to Mario, although all the skin, the gloves and the shoes were grey.

Fight
The fight consisted of Robo-Mario trying to attack Mario with punches, kicks, and the unused triple jump spin. The only way that DannyShellstar could hit Robo-Mario was by slide-kicking.

Encountering the Boss
The boss could only be found if 70 stars were collected without dying once. It is believed that storywise, the Koopa Troop would have sent out Robo-Mario as a way of stopping Mario, as the stars had been too easy for him to get.

Theorising
The fight is theorised to have been removed due to its high difficulty, as not everyone would know of the slide-kick's existence.

The boss may also be a response to the many Mechanized versions of Sonic the Hedgehog that were made over the years, such as Metal Sonic.