Rura Penthe inmate at the time of Kirk and McCoy's internment. She was a duplicitous Chameloid, or shape-shifter, who tried to use Kirk to escape the frozen planet. When Kirk figured out her plan, she "changed" into the captain's form and proceeded to fight Kirk, mano a mano. Martia -- still in Kirk form -- was killed by the Warden's disruptor blast when he arrived to eliminate all witnesses of the crime.