Origins of the "NOPE"-UFO ? ( ** spoiler alert ** )

Trevor James Constable's "Sky Critter Theory" is perhaps one of the strangest theories advanced as an explanation for the UFO phenomenon. Trevor James Constable was one of the proponents of the theory, claiming that UFO's came from a parallel universe known as Etheria and that there were two categories of UFO, some were machines and others living creatures. These invisible creatures he called "Sky Critters" and that they live in the atmosphere. Constable claimed to have captured both types of UFO on film, while working with James Woods during the 1950's and 60's. He wrote several books on the theory "They live in the Sky" in 1959, under the pen name Trevor James, and "Sky Creatures-Living UFO's" in 1978.