- Grey skin
- Small eyes in deep recesses in the skull
- Genetically engineered by the Church
- Seven feet tall
- Bulbous heads
- Mouthless faces
- Had four large fingers
- Often produced highly eerie rattling sounds
- Were "memory-proof"; anyone who saw them would instantly forget them when they looked away
- Possessed powers of post-hypnotic suggestion
- Could absorb electricity, increase the voltage a hundred-fold and fire it from their hands
- Culture centers on prophecy & doctrine tied to preventing the question “Doctor who?”
- Started in Earth's distant future as Confessional Priests
- A renegade sect became obsessed with preventing the Siege of Trenzalore
- Travelled back in time, influencing human history over a long period of time
- Attempted to create a fixed death for the Doctor at Lake Silencio
- The Doctor implanted a post-hypnotic suggestion into footage of the Moon landing;
- All were forced to flee the Earth, as Humans would kill them on sight
