Extraterrestrial energyzoa hypothesis (Ufology)

The extraterrestrial energyzoa hypothesis (ETZH) is an alternative hypothesis to the extraterrestrial hypothesis, speculating that some UFO phenomena can be explained as contact with energy-based lifeforms that live in interstellar space ("energyzoa"), as opposed to biological lifeforms from other planets travelling in physical spacecraft. This hypothesis is derived in part from Trevor James Constable's early work studying what he termed "Sky Critters".