Kohm

The Kohms were the Communists of Omega IV. They were engaged for many years in conflict with the Yangs. In 2268, the Kohms enlisted the help of Ronald Tracey in their defence against the Yangs. James T. Kirk soon learned that the Kohms and Yangs were the survivors of a planetary war extremely similar to the Cold War Humans avoided fighting in 1991.(TOS episode: "The Omega Glory")

It was unknown if the Kohms were from 20th century Earth, or had evolved in the exact same way as Humans.