An elemental is a being composed of one of the four classical (or "pure") elements—air, earth, fire, and water—or of a combination involving classical elements. These creatures are typically inhabitants of the inner planes. The combinations can be either of two classical elements (the para-elementals) or of a classical element and the energy from one of the energy planes (the quasi-elementals). Neverwinter Nights only includes the four basic elementals, leaving the para- and quasi- elementals to the custom content makers.
Since elementals do not depend on the functioning of organs, they are immune to critical hits, disease, mind-affecting spells, paralysis, poison, and sneak attacks. In addition, the larger and older elementals tend to have damage reduction.
See also: Category:Elementals