They were among the second generation of genetically engineered Klingon/Romulan hybrids created on the Chal colony. In addition to the qualities inherited from their parent species, the race had the addition of Human organs that were harvested from prisoners obtained by both the empires. Their immune systems were also very advanced and resisted the effects of stasis. (TOS novel: Dark Victory) The race appeared as humanoids with the distinctive Klingon forehead ridges and the pointed ears that marks their Romulan ancestry.