The R'Zikk are an alien race in the fictional Space Voyage 2245 universe. Although widespread, they are extremely mysterious compared to other species and civilizations encountered by humanity's Space Condominium.
Physically, R'Zikk are vaguely insectoid and breathe methane rather than oxygen. To human eyes they are extremely hideous. Their carapaces are transluscent, revealing the pulsing organs inside. Scilia along R'Zikk undersides squirm constantly while fetid liquids drip from all six of their eyes. The series has never actually portrayed one of the R'Zikk on screen (presumably because of budgetary considerations).
No one has ever found a way to tell individuals apart. R'Zikk language remains undecipherable, although R'Zikk themselves have little trouble learning other tongues. Regions where the R'Zikk hold sway are scattered all over known space, and all treat those places with respect due to the species' high tech base as well as their willingness to use deadly force.
Yet trade exists. R'Zikk are willing to trade knowledge, but only on their own terms, which are generally baffling. Sometimes they demand odd quantities of raw materials. Other times they demand to hear what the prospective buyer considers humor--sometimes for days. There have been occasions when R'Zikk negotiators demanded individuals (usually never seen again), or limbs or peculiar errands be performed--like ten persons of specific types go to a certain place and speak something unintelligible to what looked like a tree. Some seeking to trade with the R'Zikk have been instantly killed, while many more are simply ignored.