Non-corporeal lifeform

A non-corporeal lifeform was a species composed of various forms of coherent gas or energy. Some non-corporeal entities absorbed and utilized energy directly from their environment. 

Others, such as Redjac or the Beta XII-A entity, derived sustenance from the emotions of humanoid lifeforms. The dikironium cloud creature of Tycho IV forcibly extracted the corpuscles of iron-based blood and fed on that. 

Generally, non-corporeal species did not utilize technology, compensating with intrinsic physiological capabilities. Some non-corporeal races had apparently evolved beyond the need for sustenance, and wielded substantial control over space and time. 

The planet Meridian and its inhabitants spent sixty years in a non-corporeal state. 

During the original 's mission, the crew encountered a species referred to as "Wisps." They had the ability to take over the bodies of humanoids, one notable exception being Doctor Phlox. 

In early 2374, Kes became a non-corporeal lifeform after USS Voyager's encounter with Species 8472 in the Delta Quadrant, and the growth of her telekinetic, or psionic abilities.