Ozor Mox and Meezor Mox.
The Mox are a species of alien found on Planet X during the 23rd century. There are three different types of Mox, who fought each other in the Mox Civil War. The Ozor Mox and the Meezor Mox brought each other to the brink of extinction, followed by the Koozer Mox taking control of the planet, as they were out of the conflict until then. Some time after Return to Planet X, it can be assumed that the Koozer Mox were in dominant control over the planet.