A lesser regiment of the Imperium of Man's Imperial Guard, notable for its exceedingly large complement of curious Guardsmen who ask one too many questions, usually beginning with the phrase "Excuse me, Commissar..."
This regiment is also notable for its soldiers succumbing to the highest blamming rate out of any regiment, and yet the Guardsmen still don't learn to keep their mouths shut. However, despite their frequent and sometimes heretical queries to the nearest Commissar, they are mostly harmless to the Imperium and do their job only slightly sub-par compared to other regiments.
Zathras have managed to find their ways into all level of Imperial society and beyond. Members of the family have been spotted in the commissariat, amongst the Astartes, the Sororitas and into the Xenos including Tau and Necron. There has even been a Chaos Marine Zathras spotted.