The Dover Demon is currently a classic cryptid, with a variety of theories abounding as to what it was or is. Early ufologists first promoted speculation that the creature was an alien or some sort of mutant hybrid, perhaps one created as a result of a human experiment and escaped.Others theorize that it is really a being from another dimension, accidentally transferred into our world through a dimensional warp. It has been speculated by various ufologists that the Dover Demon was a Grey, due to its similar appearance.
One zoological answer that has been proposed is that it was a newborn moose. One skeptic wrote that the description of the creature's head matched that of a baby moose. Among several shortcomings of the moose explanation is that the descriptions of the Dover Demon clearly discerned fingers, while all moose, being artiodactyls, have only hooves.
Loren Coleman disputes this theory, stating that at the time of year of the sightings, yearling moose are much larger, and no moose records exist for eastern Massachusetts for the spring of 1977. Coleman additionally points out that all the witnesses had separate experiences, did not talk to each other before investigators interviewed them, and did not necessarily agree on exact descriptive details of the sighting. No conclusive evidence has been found for the existence of the Dover Demon.
The Dover Demon bears similarity to the Mannegishi creature, which is native to the mythology of the Cree Indians in Canada. Coleman also notes that cryptozoologist Mark A. Hall links the Dover Demon to other sightings of aquatic beings from around the world, often lumped under the moniker "merbeings". It is also suggested to be a Backoo, a mythical spirit creature from Caribbean legends due to similarities in the body structures.
During the spate of American sightings in Dover in 1977, all the witnesses were teenagers. This has been pointed out often in analyses of the Dover Demon sighting phenomenon. Writers with a new-age or spiritual bent often write of it as a poltergeist-type being, something with a strong field of spiritual energy that naturally connects it with the young. This reflects a recurring theme from the annals of cryptozoology, this being one of many entities whose sightings all befell witnesses from the same age group. An unfortunate comparison is made to the Owlman incidents, but skeptics rightfully point to the Owlman episodes having elements of pagan prankishness in evidence in those British events. In reality, sorting for age groups and other demographics elements can be found underlying any witness series.
Because all the witnesses were teenagers, many believe it to be a hoax, and suspect that a group of high school classmates of collaborating to make up the story.