The Geno'Karam, most commonly known as Genos, but often known as ghosts, pales, or, in a far more unappreciative culture, skinheads, are a race of near-reptillian and amphibean bipedal monstrosities. They come from the seventy-eighth moon of Kara, known as Gen (hence their name, Geno Karam).
Their homeworld is abundant in life, but like Earth, only one species has the gene HAR1, the gene which lets a species evolve sapience after sentience. Geno is also the largest moon of Kara, the fifth to support millions species of animals that are not microscopic, and the second supporting sapient life.
Geno is a giant rainforest on one side from north to south pole, and a wasteland on the other, from which the Geno'Karam inhabit, how this came to be, is unknown to the primitive species, but largely assumed they migrated there by Citadel species.
They were once great warriors and ruling over the jungles of Gen, with large structures pointing thousands of meters in the air, that often crash into the ground due to age, or in two cases of asari ships fleeing from the hunters of the Geno'Karam.
Some sections of rain forest grow over miles of city blocks and palaces, although known seem to have religous meaning. The structures are normally marble or other types of stone, seemingly similar to Roman and Greek structures.
The Geno'Karam seemed to have been split between seven factions or countries, each one at peace with each other and seemingly past any form of war. Due to them having no religion, they only worked on advancing after what could of been a gigantic war of epic battles, likely consuming nations and leaving the final seven in a large alliance.
What happened to them is unkown, but they dropped back in production, warred against each other, nearly destroying half the planet even without weapons of mass destruction (or anything beyond melees and catapults, and burning each other out).
They crushed each other into the ground and forced all but one nation into the darkness of the other side of the planet. The nation that stayed in the jungles seemingly died out, or dropped into very low numbers, not enough to keep warring against their former allies.
All that's left of the old Geno'Karam is canniblistic beasts, who constantly war against themselves and eat each other. The wars are seemless, nothing but the will to kill is known other then the occasional need to eat, which fares between years. When a tribe does need to eat, however, they attack and destroy other clans.
When no other clans are available, they eat each other, even children and women. Whatever caused this happened merely years before humans were introduced to the galatic community.
After the Red Legion was unable to find the more peaceful civilization of geno'karam in the dense jungles of Gen, the Red Legion began conscripting the cannibalistic and much more fierce geno beasts of the darker reaches of the moon, taking entire squads to take down more resistant and soon to be slaves.