R4-G9, also known as Geenine, was a bronze-domed. R4-series astromech droid maintained by the Jedi Order on Coruscant during the Clone Wars. Like many Jedi R4-series droids, Geenine had an R2 series dome.
R4-G9 was originally assigned to Aayla Secura, and it operated aboard her blue-hued Eta-2 interceptor. During the search for Asajj Ventress, Secura loaned the starfighter to Obi-Wan Kenobi. R4-G9 flew with Kenobi to pick up Anakin Skywalker on Naboo, before rendezvousing in the Karthakk system. Following the resolution of Obi-Wan's quest, he switched to a red-hulled interceptor, though apparently kept Secura's starfighter as a backup.
When Obi-Wan was tasked with tracking down and eliminating General Grievous, he flew with G9 to Utapau in the Outer Rim Territories as he had lost his original R4 droid in battle. There, he learned that the Separatists had assumed control of Pau City, and ordered G9 to perform a diversionary tactic. G9 piloted the interceptor off the planet alone, returning to Vigilance while Obi-Wan remained on-world to locate Grievous.
R4-G9 would of probably went on to serve in the Imperial Navy.