Wight

Wights are a rare kind of naturally created undead. A wight is born when the death of a living creature is so horrific and traumatic, that a curse is created, raising the creature from the dead as a malignant force. Wights are often intelligent creatures and their capabilities are based on their previous life.
One of the most dangerous recorded kinds of wights are the Consuming Maw.  Their creation has been documented as one reproducible by starving a halfling through means of excruciating torture.  Once turned, their bodies become capable of devouring any material, organic or not, with an insatiable appetite that never ends.