Consuming Stinky Meat provides you with a significant duration of Polymorph immunity. Two seconds of immunity is provided for every pixel of meat eaten, which is the longest duration granted of any material ingest effect in the game. This is the only way to gain immunity to the effects of Polymorphine, Chaotic Polymorphine, and Unstable Polymorphine.
When you unload the area by leaving and then return, stinky meat corpses will be replaced by blood which inherit the corpses' colours.
Sources
Stinky Meat can be found as the corpse of these enemies.