One of two human-like peoples on Omega IV, the Kohms were settled villagers locked in an ancient struggle with the wild Yangs and were defended by the renegade Starfleet captain Ronald Tracey, who used his own phaser on their behalf.
The Kohms appear in the Original Series episode The Omega Glory. Omega IV was devastated long ago by a bacteriological war, and the survivors' descendants live extraordinarily long lives; one Kohm, Wu, says he is 462 years old.
In 2268 the Enterprise finds the starship Exeter in orbit, its crew reduced to crystals by a disease brought up from the surface. Captain Tracey, the only survivor, has broken the Prime Directive by defending the Kohm villages against the Yangs with his phaser, hoping to sell the secret of their longevity. McCoy finds there is no secret, only natural immunity built up over generations.
The planet's history closely parallels Earth's: the Kohms correspond to Communists and the Yangs to Yankees. The Yangs overrun the villages and reveal a tattered flag and garbled sacred words that Kirk recognises as the United States Constitution.