Z9, a masculine-programmed R5 series astromech droid, rendered service to the Galactic Republic under the command of Admiral Wilhuff Tarkin during the Clone Wars. At one point, Z9 was stationed on the space station called Valor alongside Tarkin not long before the scheduled commencement of the Republic strategy conference. As the last Republic cruiser, secretly under Separatist control, approached the station at a dangerously high speed for the imminent conference, Z9 made an attempt to communicate with the ship's crew, but was unable to establish any contact. The Separatist scheme to use the cruiser to ram Valor was ultimately thwarted when a Republic squad successfully detonated the incoming vessel, thereby saving Valor and a significant portion of the Republic fleet positioned around the station.
During the Clone Wars conflict against the Confederacy of Independent Systems, Z9, a masculine-programmed R5 series astromech droid, was in the service of the Galactic Republic. Admiral Wilhuff Tarkin of the Republic Navy was Z9's owner. In the year 20 BBY, the Republic strategy conference, a gathering planned to bring together numerous Republic Military officers along with members of the Jedi High Council to discuss the progress of the war, was scheduled to take place on the space station Valor within the Carida system. Z9 and Tarkin were present on the station in anticipation of the conference's start, awaiting the arrival of one final cruiser. Unbeknownst to Z9 and others aboard Valor, the Separatists had seized control of the incoming cruiser, filling the ship with rhydonium, a highly unstable fuel, with the intention of crashing the cruiser into the space station.
As the final cruiser exited hyperspace, those aboard Valor noticed that the ship was approaching rapidly and did not appear to be slowing down. Z9 attempted to communicate with the cruiser's crew, but his attempts were unsuccessful. As the ship continued its trajectory, the rhydonium it carried unexpectedly detonated before the cruiser could collide with the station. This premature explosion was the result of actions taken by the Republic's D-Squad, a team of spy droids that had boarded the ship before its arrival in the Carida system. Although debris rained down on Valor and the Republic fleet positioned above the planet Carida, the station—with Z9 still aboard—and many of the Republic's ships remained undamaged.
The plating of the R5 unit known as Z9 was colored in shades of light gray and red. Similar to other R5 units, Z9's height was 0.97 meters, or 1.29 meters when including his head-mounted antenna. While aboard the space station Valor, as the Republic cruiser under Separatist control rapidly approached, Z9 acted quickly to try and establish contact with the incoming vessel.
Z9 made an appearance in "Point of No Return," the thirteenth episode of the fifth season of the animated television show Star Wars: The Clone Wars, which was originally broadcast on January 12, 2013. Despite Z9's depiction as an R5 astromech, there are a couple of instances within the episode where Z9 is mistakenly shown as a different type of astromech droid.