Cadet T'nag was a 23rd century individual who was an upper-class student at Starfleet Academy in 2258, in an alternate reality. T'nag was one of a number of cadets who were pressed into service as Starfleet officers by an emergency order from Admiral Richard Barnett during the crisis in the Vulcan system. T'nag in particular was assigned to serve aboard the ill-fated USS Antares, one of the fleet of ships destroyed at planet Vulcan. (TOS novelization: Star Trek) T'nag is likely an alternate reality version of T'nag, an enemy of Kor, Kang and Koloth.