#the-cryptid-files

1. distribution anomalies - animals in places they shouldn’t be; e.g anomalous big cats of the UK

2. undescribed, unusual, or outsized variations of known species -  e.g. giant anaconda (Amazonia); spotted lions (East Africa)

3. survivals of recently extinct species - e.g. ivory-billed woodpecker, presumed to be extinct in 1960; Stellar’s sea cow, presumed to be extinct in 1770; both of which are occasionally claimed to have survived into the present

4. survivals of species known from the fossil records into modern times - e.g. mokele-mbembe (Central Africa) is sometimes described as a living dinosaur

5. lingerlings, or survivals of species known from the fossil record much later into historical times than currently thought - e.g. wooly mammoth, presumed to be extinct in 12,000 BCE, but is occasionally purported surviving into later eras

6. animals not known from the fossil record but related to known species - e.g. Andean wolf; striped manta ray

7. animals not known from the fossil record nor related to any known species - e.g. Bigfoot; sea serpents

8. mythical animals with a zoological basis - e.g. griffin, partly inspired by dinosaur fossils of Central Asia

9. seemingly paranormal or supernatural entities with some animal-like characteristics - e.g. Lizard Man; Mothman; Black Dogs; faeries

10. known hoaxes or probably misidentifications - e.g. jackalope, possibly inspired by rabbits infected with Shope papilloma virus, which causes anter-like tumors

Exclusions:

1. insignificance - cryptids must be big, weird, dangerous, or significant to humans in some way.

2. lack of controversy - someone needs to observe a mystery animal and someone else needs to discredit the sighting. cryptozoologists function as interventionists between the witnesses and skeptical scientists.

3. erratics - the out-of-place alligator...that turns up in an odd spot, undoubtedly through human agency, is not a zoological mystery...[i]f someone discovers a new species of alligator that lives only in sewers, that is a different matter.

4. bizzare humans - e.g. zombies

5. angels or demons - ...the paranormal is admitted only if it has an animal shape (a werewolf sighting, which might involve a real dog, or wolf, or a mystery canid.

The Dover Demon of Dover, Massachusetts has been described as a large, glowing eyed creature, with a large watermelon head with no features, a tan hairless body, and long tendrily appendages. The first, and only, sightings occurred one night on April 21, 1977.  First, the creature was seen by William Bartlett, who drew the most famous illustration of the Demon, and “swore on a stack of Bibles” it is what he saw. Later, John Baxter was walking home when he stumbled upon a similar creature, that he first assumed to be a neighbor with a deformed head due to a childhood disease, but there was no response after he called out. His illustration resembles Bartlett’s. Even later that night, Abby Brabham saw a similar creature. All three sightings took place near water, and when mapped make a two mile straight line. Since the witnesses were all teenagers, it was believed to be a hoax, or a foal or moose calf. However, it wasn’t foaling season and there were only two moose sightings in all of Massachusetts that year. There have been no sightings since. 

“The Dover Demon.” Strange New England. http://www.strange-new-england.com/2015/10/21/dover-demon/#more-125

Sullivan, Mark. “Decades later, the Dover Demon still haunts.” Boston.com. http://archive.boston.com/news/local/articles/2006/10/29/decades_later_the_dover_demon_still_haunts/

“Dover Demon.” Wikipedia. https://en.wikipedia.org/wiki/Dover_Demon