Fast, bloodthirsty, rebellious.

From: "Priest" (2011).

Many hundreds of generations have lived underground, and therefore have lost their eyes. They move very unpredictably, and they are much faster than humans, have a skeleton under their skin, and it's very different from ours, have superhuman proportions, as well as fine hearing and sense of smell to navigate without sight.

(This is an official branch, akin to ghouls, serving their masters, during the day, while they sleep).