Type: Boss Monster/Partner
Weapon: None/Rock Cannon (Hero Mode Only)
Bio: The first Pokemon ever created by Arceus and Satoshi. It may be small in stature, but this guy packs a punch. He is the strongest in Arceus's Army and is the Guardian of the 1st Gate in the Overthere.
Hero Mode: When Rhydon was mind-controlled by Bill Cipher, he became a mix of Bill and Rypherior. He killed all of Luigi's friends when he was gone. When Luigi came back, he had the ultimate battle with Rhydon and Bill and revived his friends.