Void elementals are alien beings whose bodies are hollow spaces encased in black, rubbery membranes. Their logical minds are largely devoid of emotion, particularly empathy. Most are cold-blooded killers pursuing inscrutable goals that few sane creatures would understand.

Void elementals vary in appearance—they usually manifest with pillar-like bodies and numerous tendrils, though any given void elemental may instead have a shape akin to that of a particular aberration, be it an aboleth, a cloaker, a darkmantle, or something else altogether. Features on a void elemental's body manifest as knobs, suckers, or other deformations of its rubbery hide.

A void elemental has the same height and weight as a fire elemental of the same size.