Acid

Acid is grisly liquid that can cause major and permanant scarring, and possible death.

In novels
The Do'Urden patron and weapon master, Zaknafein as a Zin-carla willingly fell into a pit of acid to prevent himself from murdering his son, Drizzt. In this battle, Guenhwyvar, Drizzt's magical panther, also fell into the same chasm, but, with a trip to the Astral Plane, Guenhwyvar made a full recovery.