TC-16 was a silver-plated protocol droid. He was the property of Trade Federation Viceroy Nute Gunray, and resided within Gunray's citadel located on Cato Neimoidia during 19 BBY.
During the Battle of Cato Neimoidia, the Republic forces captured him. Subsequently, he functioned as a translator for Jedi Generals Anakin Skywalker and Obi-Wan Kenobi during their mission to Charros IV. Later, the Xi Charrians repaired and modified him, after which he was assigned as a translator to Aurek Team.
After witnessing the demise of Aurek Team at the hands of Darth Sidious, coupled with his own unexpected shift in allegiance, TC-16, who was spared, seemingly experienced a mental breakdown, at least by droid standards. During a conversation with C-3PO, he foretold the arrival of dark times and the blurring of the line between good and evil. He then suggested that C-3PO should accept a mind wipe if ever offered, as the alternative would be unyielding fear and bewilderment.
TC's posture was stooped because of a damaged pelvic joint, and he also suffered from corrosion in his internal circuitry.