Arthuritis

Arthuritis is an imaginary illness. D.W., Bud, and Emily pretended that Brobots were trying to get to Earth from the Moon to give everyone Arthuritis when they ate infected Ziloonian Crystals. The S.S. Dwembiludy is equipped with technology to cure Arthuritis.

Trivia

 * D.W. first mentioned 'arthuritis' (with a lowercase 'a') in "Crushed".
 * It sounds like arthritis but is nothing like it.