Doctor Carter is the surgeon of the USS Exeter in The Omega Glory, seen only in a final log recording warning boarders that the ship's crew has been killed by an alien disease.
Doctor Carter is the medical officer of the starship Exeter in the Original Series episode The Omega Glory. The Enterprise finds the Exeter in orbit of Omega IV with no one aboard, only uniforms filled with white crystals.
In sickbay the landing party plays the last log entry. Carter, plainly dying, explains that a landing party brought back an infection from the planet and that everyone aboard is dead. He warns whoever is watching that they are now infected too and that their only chance is to go down to the surface.
McCoy finds that the crystals are what remains of a human body once the water is removed. Carter's message sends Kirk, Spock and McCoy to Omega IV, where they find Captain Ronald Tracey, the sole survivor.