Caxtarid

The Caxtarids were a humanoid species with metallic red eyes and hair. They were experts in the creation of living torture machines, such as the Prompter of Confessions and the Manacle of Flesh.

History
The Caxtarid invaded Kapteyn 5 and enslaved the Kapteynians, exterminating four of the indigenous sentient species. (NA: The Room with No Doors)