This post is going to pick right up from here on the blog with old foes stirring as ancient lands rise from the depths of legend on Mars!
I've been re reading the Leigh Brackett Mars stories again and going through Night Owl Workshop's Beasties: Loathsome Horrors. And Thomas Denmark also included four NPC's and two of these guys are humanoid serpent priests. Now in the past I've used Serpent Men on Mars as being one of the forbidden races that exist near the poles. Thier pyramids and zigguarats dotted the landscape around their minor empires and kingdom's holdings.
King of Rats Serpentman on Deviant art.. Used without permission.