X-10 was a droid member of the Nihil marauder organization during the time of the High Republic Era. When a number of Nihil, including Eye of the Nihil Marchion Ro, were stationed on Quantxi, the Junk Moon of Ord Mantell, X-10 remained aboard their vessel. After the Nihil on the moon came under attack from the resident Junk Mavens, Ro ordered the marauder Zagyar to have X-10 ready the starship.
X-10 first appeared, albeit unidentified, in the third issue of the Star Wars: The High Republic Adventures comic series, written by Daniel José Older and published on April 7, 2021. In issue 5, Marchion Ro orders for X-10 to have their ship ready, though it was not confirmed if X-10 was the droid that was seen with Zagyar before. Older later confirmed on Twitter that the droid seen with Zagyar was indeed X-10 in the scripts.