Rukshi (Rook-she)

A species that achieved technological enlightenment at the same time as when Man was first banging on logs and scrounging around for berries for nourishment, this reptilian-esque species grew at a rapid pace, turning their once green and lush earthen world into a sphere of bright steel and platinum in only a few several generations. They synthesized all of their nourishment, regulated the atmosphere, and supervised plans for interplanetary colonization. But something went horribly wrong.
The species itself existed of a stern and immovable caste system. At the top, managed by the most intellectual and manipulative of their race, and at the bottom, where the grand majority of the populace lied amongst the filth and decay of a pollution-filled and wasteful industrial era. A seperate sect of Rukshi rose to great prominence, labeling themselves as the Zeftol, native tongue for Harbingers. These crude barbarians were just as manipulative as the Rukshi elites, and took advantage of the masses as they led a rebellion against their dictators.
The first of the riots were devastating. Massive skyscrapers, world-reknowned, crumbled in fire and ash. Science facilities, so superior in their research, Human facilities from the 21st century appeared as if they were still inventing the wheel, were bombed, thousands of years worth of research destroyed in just a few great blasts. This was the beginning of the end for the Rukshi and their home.
After just a few short months, most of the gleaming world was turned to a smoldering fire, and the last of the most advanced minds had little option left but to abandon their world. In only a few days, legions of spacecraft took to the heavens, filled with only a few hundred thousand Rukshi. These Rukshi breathed the last of their planets air, witnessed the final glimpse of white and gold that remained, and vanished from their home, never to return.
For many millenia, these Rukshi wandered the cosmos. So much information, lost, and it had to be recreated. Luckily, these Rukshi were the greatest minds their species had ever developed. It didn't take long for them to regain the lost knowledge, and since they feared of the same destruction taking them again, instead of embracing their diversity - they eliminated it. Cultural backgrounds and family histories were abondoned, and only intellect prevailed. By the time humans had established a galactic foothold, the Rukshi were bred to perfection - in their eyes. Unfortunately, this left little room for an open mind, and arrogance spread like a plague amongst them.
All in all, the Rukshi are an impossibly intelligent race, their power coming from their minds, but that doesn't mean that their pre-civilized traits are completely gone. They still grasp onto their almost reptilian roots, and are incredibly agile. Other physical traits enable them to have a tougher "skin" than humans, and are resiliant to most biological ailments, such as a virus or bacterial infection. It would be best to avoid any kind of physical altercation with these aliens, for their sheer guile and agility could prove most deadly.