The Ur-Quan Kohr-Ah are one of two subspecies created from the original Ur-Quan strain by the malicious Dnyarri. Nearly identical to their Kzer-Za brethren, the most noticeable difference between their two is their skin tones - Kzer-Za are green while Kohr-Ah are black. However, another difference is seen in their arms, where only Kohr-Ah appear to possess actual hands. At least part of their body is covered by a sheath which retracts when the creature experiences intense pain, along with the oozing of their talons.
The "Black Ur-Quan" are not natural. They were genetically engineered by the Dnyarri 20,000 years ago to serve them as their "effectors", to fill the role of the builders and warriors for the growing Dnyarri Empire. Unfortunately for each of the new Ur-Quan subspecies, the genetic manipulation permanently divided them and exterminated the original species once and for all. Being that the Dnyarri did not care to name either creation, it was not until the slave revolt against their oppressive, mind controlling masters that this species named themselves after Kohr-Ah, after a hero - a starship captain - who survived the revolt against their oppressors, and whom is credited with the development of the Eternal Doctrine, which all Kohr-Ah adhere themselves to.
Similar to their green-hued cousins, the Kohr-Ah are driven by a severe need to prevent anything like the Dnyarri Slavery to ever happen to their species again. Unlike the Kzer-Za, however, the Kohr-Ah see genocide of other sentient races as the only reliable solution.
However, they also believe in interstellar reincarnation, preventing them from having anything remotely related to an ethical problem to this, as they believe that each alien they kill could - and will - eventually be reborn as an Ur-Quan.
They soon burned the world of Yuptar, a former ally of the original "brown" Ur-Quan during the heyday of the Sentient Milieu, obliterating them utterly. However, both the Kohr-Ah and the Kzer-Za arrived above the homeworld of the Mael-Num at roughly the same moment, and a standoff occurred. No one remembers who fired the first shot, but it led to a massive conflict during which the Mael-Num managed to escape into the starry night. This was the beginning of the Doctrinal Wars. Were it not for the acquisition of a legendary Precursor item, the Sa-Matra, both species would likely have annihilated each other. However, during the first Doctrinal War, the Kzer-Za discovered the Sa-Matra, which proved to be decisive in combat, and instead of eradicating their brethren, chose to banish them instead, forced to circle the galaxy in opposing fashion to the Kzer-Za. Now, the two races move in opposing directions around the galaxy, and when they meet again they would ceremoniously begin the war once more to find out which subspecies' doctrine was superior.
In the wake of their travels, they have left half of the galaxy devoid of sapient life, primarily through the use of their Marauder starships.