The serpentfolk, known also as Yuan-Ti, are an evil race of humanoid serpents. Two thousand years ago they started to get powerful with the help of Rovagug, the evil god of wrath, disaster and destruction. They were thwarted by a nameless group of Paladins and Clerics who were able to banish Rovagug. This dimensional prison is sealed by the Great Rod of Holding.
The serpentfolk fled / were banished back to the shadowplane and have not been seen on the material plane for eons. Recently they have surfaced in the Gray Mountains and in Rodryq’s homeland