The common description is that of a bipedal kangaroo-like or wyvern-like creature with a horse- or goat-like head, leathery bat-like wings, horns, small arms with clawed hands, legs with cloven hooves, and a forked or pointed tail.

Brian Regal, a historian of science at Kean University, theorizes that the story of Mother Leeds, rather than being based on a single historical person alone, originated from the reputation of the local prominent Leeds family in the southern portion of the colonial-era Province of New Jersey, where religious-political disputes became the subject of folklore and gossip among the local population.

As a royal surveyor with strong allegiance to the British crown, Leeds had surveyed and acquired land in the Egg Harbor area, located within the Pine Barrens.

[17] Starting in the 17th century, English Quakers established settlements in Southern Jersey, the region in which the Pine Barrens are located.

The competition between the two men intensified when, during 1733, Franklin satirically used astrology in his almanac to predict Titan Leeds' death on October of that same year.

The Leeds family crest depicted a wyvern, a bat-winged dragon-like legendary creature that stands upright on two clawed feet.

The fearsome appearance of the crest's wyvern and the increasing animosity among local South Jersey residents towards royalty, aristocracy, and nobility (with whom family crests were associated) may have helped facilitate the legend of the Leeds Devil and the association of the Leeds family with "devils" and "monsters".

In the early to mid-19th century, stories continued to circulate in southern New Jersey of the Leeds Devil, a "monster wandering the Pine Barrens."

)[18][19] A newspaper from 1887 describes sightings of a winged creature, referred to as "the Devil of Leeds", allegedly spotted near the Pine Barrens and well known among the local populace of Burlington County, New Jersey: Whenever he went near it, it would give a most unearthly yell that frightened the dogs.

"That thing," said the colonel, "is not a bird nor an animal, but it is the Leeds devil, according to the description, and it was born over in Evesham, Burlington County, a hundred years ago.

I never saw the horrible critter myself, but I can remember well when it was roaming around in Evesham woods fifty years ago, and when it was hunted by men and dogs and shot at by the best marksmen there were in all South Jersey but could not be killed.

[3] Joseph Bonaparte, elder brother of Napoleon, is also claimed to have seen the Jersey Devil while hunting on his Bordentown estate about 1820.

[3] In Greenwich Township, in December 1925, a local farmer shot an unidentified animal as it attempted to steal his chickens, and then photographed the corpse.

Among these alleged encounters were claims the creature "attacked" a trolley car in Haddon Heights and a social club in Camden.

[31] The widespread newspaper coverage created fear throughout the Delaware Valley prompting a number of schools to close and workers to stay home.

[33] Skeptics believe the Jersey Devil to be nothing more than a creative manifestation upon the imaginations of the early English settlers in South Jersey, with plausible natural explanations including: bogeyman stories created and told by bored Pine Barren residents as a form of children's entertainment; the byproduct of the historical local disdain for the Leeds family; the misidentification of known animals; and rumors based on common negative perceptions of the local rural population of the Pine Barren (known as "pineys").

Gangs of highwaymen, such as the politically disdained Loyalist brigands, known as the Pine Robbers, were known to rob and attack travelers passing through the Barrens.

He recounts occasions when terrified hikers mistook him for the Jersey Devil, after he covered his whole body with mud to repel mosquitoes.

[42] Medical sociologist Robert E. Bartholomew and author Peter Hassall cite the infamous 1909 series of sightings of the Jersey Devil (and the subsequent public panic) as a classic example of mass hysteria begun by a regional urban legend.

[44] Writer Dan Evon noticed some similarities between the Jersey Devil and an existing megabat species found in Africa, Hypsignathus monstrosus.

[45] Gordon Stein in Encyclopedia of Hoaxes (1993) noted that the alleged footprints of the Jersey Devil during 1909 resembled a horse's hoof.

So when the museum proprietor, T. F. Hopkins, admitted that it was in danger of closure unless Jeffries came up with something to boost attendances, the publicist decided that a captive Jersey Devil would be the ideal crowd-puller.

[47] During 1909, Jeffries with his friend Jacob Hope, an animal trainer, purchased a kangaroo from a circus and glued artificial claws and bat wings onto it.

Dorson specifies that the qualifier must: exist in oral tradition, inspire belief and conviction, become personalized and institutionalized, be fanciful or mythical , and contain a "comical side," which endears it to the American public.

[55][56] This same trend towards cultural incorporation is further exemplified by the Jersey Devil's appropriation in toy lines, such as its inclusion as a vinyl figure in Cryptozoic Entertainment Cryptkins blind box,[57][58] as well as its application as a motif by Six Flags Great Adventure for their Jersey Devil Coaster developed by Rocky Mountain Construction.