Skull jehts are risen from the grave by nanite technology. These creatures were once the adaptive race of beings called jehts and were mutilated and tortured for the sake of science and still seem to harbor some emotion towards their oppressors. Although controlled by the nanites, these undead beings will somehow overpower their programming and attack their enemies.
The nanite reconstruction may only build what’s essential for these creatures to function, but their make up is that of a durable jeht war machine. They are extremely quick, durable, and capable of breathing fire or casting a debilitating resonance that can drop many into a coma like state.