Z-Mu Squadron was a Alpha-class Xg-1 Star Wing squadron used by the splinter government fleet of Grand Admiral Demetrius Zaarin. It fought at the Battle of Parmel during his insurrection. At least two TIE pilots of the squadron were members of the Emperor's special reserve guard, a cadre of elite pilots serving Emperor Palpatine himself. Imperial Intelligence discovered the information, which led them to believe that every level of the Imperial Military hierarchy had spies.