An X-Naut is an alien race from Paper Mario: The Thousand-Year Door. After Mario departs from his boat and steps into Rogueport, he finds Goombella being chased by X-Nauts and their leader Lord Crump, a sort of X-Naut general. Mario decides to help Goombella to escape from the X-Nauts. They act as footsoldiers and salute their leader by crossing their arms over their chest, making an X. They work for their leader Sir Grodus to help take over the Mushroom World. Their organization is called Secret Society of X-Nauts.