Hailing from Naboo, Commodex Tahn was a human of the male persuasion. He served as a military clerk during the waning decades of the Galactic Republic. Prior to the final year of the Clone Wars, the death of his father led Tahn to resign from his position in the Republic military and take up the family business as a mortician. At the close of the Clone Wars, he was responsible for preparing the body of Padmé Amidala, the former queen and senator of Naboo, for her burial. Shortly before her demise, Amidala was carrying twins, fathered by Anakin Skywalker, a Jedi Knight who had embraced the evil. Amidala successfully delivered her offspring, who were hidden away to prevent Skywalker from discovering them. Tahn, in his capacity as a mortician, was charged with altering the corpse to give the impression that Amidala was still pregnant, ensuring that Skywalker would not suspect that his children were still alive. Following this event, he chose to retire.
Almost two decades later, Skywalker, now known by the Sith name of Darth Vader, discovered that he had a son. Doctor Aphra, a Vader operative, visited Commodex Tahn and used torture to extract information from him. Tahn only revealed what Aphra already knew, that Amidala had given birth to a male child. However, the mortician resisted divulging the existence of a second child, a girl. Despite his confession, Tahn met his end at the hands of Triple Zero, a cruel droid allied with Aphra.