Xatoth

They live on an M class planet, tropical but a bit more dry. Half the planet is heavily lived, the other zone is savage and banded. Ecology of the land or ocean are normal despite that the Xatothian drove to extinction many species.
Description : Descendants of reptilian, but they are warm blooded. Skin show their origins, scales on their faces and body as well, color green, some are grey.
History  : Their past if fill with violence with a few period of peace. During the industrial age, they develop atomic power, space exploration came around 250 yrs ago, warp technology got stolen from the Yosqi around 140 yrs ago. They are at war with the Yosqiian for at least a century, ever since that they refuse their admittance into their society.
They are warriors, or at least are primitive in their behavior. In the other hand, they are intelligent, self preservation of their planet is a priority, cunning, opportunistic and more. Family unite exit, one male for several females, usually subservient. They believe that only the strongest must survive, malformed, sick, and old are euthanasied, now it's done cleanly. They are people of few words and also forbid any ships to cross their sectors and this without warning.
Following orders : Avoid further contacts.  Prime directive applied.