This Gundam papercraft is the RX-75 Mass Production Type Guntank. On the anime series, this unit was first developed by the Earth Federation under their top secret "Project V". As you can see, this unit can't fly and is nothing more than a fusion of a tank (bottom part) and a mobile suit for the upper torso. It requires two pilot to control it, one inside the head as the gunner and another inside the Core Fighter as the driver. Thanks goes out to the designer and reader Smiley for sending this in.