This papercraft is Great Ape (Ōzaru; lit. "Great Monkey"), a giant, monkey-like creature that Saiyans can transform into at the full moon to increase their enormous strength, based on the Dragon Ball series, the paper model is created by Carojama. The finished model stands about 80 cm tall.
Dragon Ball GT Perfect Files speculates that Saiyans were originally Great Apes who gained intelligence and took on a humanoid form. For more information please click here.