The Secret Society of X-Nauts is an evil organization that appeared in Paper Mario: The Thousand-Year Door. They also served as the main antagonists of the game and their main goal was to awaken the 1,000 year-old demon and use it to help take over the world.
For the Society's plan to work, Grodus first had Lord Crump and the X-Nauts kidnap Princess Peach and keep her held up at their base on the moon. Next, Grodus knows that he must now try to unlock the Thousand-Year Door so he sends Lord Crump and the X-Nauts back to Rogueport to search for the rest of the Crystal Stars. However, Grodus soon learns that someone has defeated Lord Crump and even got the first Crystal Star. After questioning Peach, Grodus soon learns that Mario is to blame and then sends Lord Crump and the X-Nauts to The Great Tree to find the Crystal Star. Grodus then hires the Shadow Sirens to take down Mario to prevent him from getting more of the Crystal Stars.
By the time Mario gets to The Great Tree, the X-Nauts have already taken it over, locked up all of the Punis, and even locked the front door to keep Mario out. However, Mario manages to get in where the X-Nauts attempt to stop him. Mario manages to fight his way through the X-Nauts and The Great Tree until he uncovers the Crystal Star. However, Lord Crump swoops in and grabs the Crystal Star and attempts to blow up The Great Tree. The Puni Elder manages to stop him and Crump was forced to fight Mario in his creation: the Magnus von Grapple. However, Lord Crump is defeated and is forced to report his failure to Grodus.
Soon, Grodus does some more research and learns that another Crystal Star may be on Keelhaul Key. He sends Lord Crump there and Lord Crump boards the S.S. Flavio disguised as a crew mate named "Four-Eyes". Lord Crump follows Mario around until Mario gets the Crystal Star from Cortez. Afterwards, Lord Crump, on a battleship, launches an attack on the island demanding Mario to hand over the Crystal Star. Mario, however, boards on Cortez's ship, the Black Skull, and the two sides begin fighting. Lord Crump is then challenged by Mario and is defeated by him. Lord Crump is forced to retreat and tell Sir Grodus about his failure again.