Non-corporeal

Non-corporeal (or incorporeal) is a term used to describe lifeforms or objects that have no material body or form, and which lack substantiality.

In the case of lifeforms, this term is generally used to mean that the lifeform or object in question is composed of gas or, more commonly, energy.

Due to their radically different nature, non-corporeal lifeforms generally exist in entirely different ways to corporeal lifeforms (those with solid bodies, such as Humans and Klingons). They interact with their environments differently, they often have no ability to utilize technology, and may be unable to communicate with corporeal lifeforms. They also derive sustenance in unique ways, such as the Redjac which feeds on the emotions of humanoids. Some may absorb energy from their environments, while others may have evolved beyond the point of requiring sustenance at all. Many non-corporeal lifeforms exhibit capabilities beyond those of corporeal beings, and in some cases can "tale control" of humanoid or other beings.

Examples of non-corporeal species include the Thasians, the Prophets and, to a lesser extent, ghosts.