Great ape Vegeta Dragon ball z

Great Ape (大おお猿ざる Ōzaru, lit. "Great Monkey") is a giant, anthropomorphic, monkey-like creature that the Saiyans of Universe 7 can transform into at the full moon (or a similar object) to increase their already formidable strength tremendously. Dragon Ball GT: Perfect File speculates that Saiyans were originally Great Apes who gained intelligence and eventually took on a humanoid form.[1]