Anthar was the Governor of the underground city of Caeminon on a planet in the universe of superspace.
In 2267, Anthar met with a landing party from the USS Enterprise, who had been brought to the city by Rhuna. Captain James T. Kirk asked him if he could help his crew return to their own universe. Anthar was unable to do so, but asked them how they were able to defeat the vegetable metalloids on the planet's surface. Soon afterwards, he was shot and killed by one of the creatures, which had broken into the city. (TOS comic: "Siege in Superspace")