Cryptspawn potion

Cryptspawn potions were a sort of immune-system enhancing potion that existed in the period between the Spellplague and the Second Sundering.

Description
The liquid within these potions was viscous and had a smell evocative of dead bodies.

Powers
Ingestion of a cryptspawn potion granted imbibers an enhanced resistance against all manner of diseases and poisons, as well as necrotic energy

History
In the late 15 century DR, cryptspawn potions could be found in use by many members of the Zhentarim.