Tommy Starnes was the son of Professor Starnes and his wife. Professor Starnes was the leader of the Starnes Exploration Party on Triacus in 2268. Tommy was the oldest of the surviving children from the Exploration Party and their quasi-leader. He, like the other children, showed no grief over his parents' deaths, even to the point of playing games as if there was nothing wrong.
Controlled by Gorgan, an alien he and the others referred to as the "Friendly Angel", Tommy attempted to take the USS Enterprise to Marcos XII, so Gorgan could consume more worlds and cause more death for his own evil purpose. He initially asked Captain James T. Kirk to take them to the planet, claiming to have relatives there; when Kirk explained it was outside their patrol area, he used the powers he had been given by Gorgan to induce hallucination and mental incapacitation in the crew to hijack the ship.
Once he and the other orphans were shown tapes of their parents and their graves, demonstrating to them that Gorgan was an evil force, they refused to obey him and the Gorgan was rendered impotent. Tommy and the rest of the children then returned to normal, even crying over their parents' deaths. (TOS: "And the Children Shall Lead")