Private "Colonel" T'Phai is the former military leader of the Skinnies.
T'Phai's rank is Private within the Mobile Infantry, but he is still referred to as "Colonel", his Skinnie rank, by his fellow Roughnecks. T'Phai is considered a father figure since he had a wife, who was also in the military, and two children. He believes in fighting a war so that his children wouldn't share the same fate as him.
T'Phai was an enemy for most of the Tophet Campaign under the influence of a Control Bug. He was indirectly responsible for Carl Jenkins' extended medical leave. This did not help matters when he was assigned to Jenkins' squad, the Roughnecks, during the Tesca Campaign. Not accepted initially, T'Phai received the acceptance of all Roughnecks, but Rico in the end of the first episode, not receiving Rico's approval until the end of the second episode.