C4-ZX was a 3PO-series protocol droid active during the Galactic Civil War sometime after 0 BBY. The droid was owned by the Jawa trader Ji'Ni Sil. The droid stood with its master at the Jawa Mountain Fortress on the planet of Tatooine. In 1 ABY, Ji'Ni Sil was approached by a spacer who was looking for a body casing from a R2 unit that once belonged to Peggin Dulin. The droid was actually wanted by both Imperial Commander Barrezz and Rebel Captain Bastra. C4-ZX informed the spacer that the droid casing was already sold to a miner. Despite the miner was killed by Tusken Raiders, the spacer finally managed to retrieve the casing.
C4-ZX was a non-player character in the 2003 video game Star Wars Galaxies, a massively multiplayer online roleplaying game developed by Sony Online Entertainment and published by LucasArts, prior to its closure on December 15, 2011. C4-ZX was added to the game as part of the "Legacy Quest" with the release of the "Publish 25," a.k.a. the "New Game Enhancements," on November 15, 2005.