Folk Legend
When I was little, I always used to hear legends about the New Jersey Devil. The Jersey Devil was described to be a strange creature with reptile wings and hooves. The Devil is said to live in the Pine Barrens of New Jersey, which is about an hour south of where I live; there are a lot of trees and very strange people are rumored to live in that area. The story goes that the Leeds family came to America from England a couple hundred years ago and the Leeds were desperate to have children. After the twelfth child, Mrs. Leeds got pregnant again and is said to have yelled something about that child being the devil, and when she gave birth it was the NJ devil. A lot of people say they have seen the Jersey devil all over, and mainly in the Pine Barrens area.
Ive heard this story ever since I was little. I heard it from friends, family members, camp counselors, teachers, etc. It is a very well known rumor in New Jersey, and even the NJ Devils hockey team is said to be named after the creature (most likely to give off the sense of being fierce and killing.) It is essentially a legend that anyone born and raised in New Jersey grows to learn and re-tell.
It is likely that legends like these stem from a combination of a family story and sighting of a variety of animals. The Leeds family probably did have a lot of children; maybe one died, or got kidnapped, but the rumors most likely began about something being wrong with one of the children. Additionally, New Jersey has a wide variety of animals, and a lot of forests (despite what most think.) It would be incredibly easy to mistake a horse, dog, winged animal, or even human for the Jersey Devil at night when details are hardly visible. Some speculate that the creature could actually exist and be a very rare animal species that happens to be very afraid of humans.
Another way this legend was probably formed is because the Pine Barrens is said to be a very, very strange area of New Jersey. The people who Ive talked to about the Pine Barrens and south Jersey say that there is a lot of incest and deformed people along with very odd families. It is very likely that this inspired someone, or a group of people, to create a humorous and scary legend about this area that would last for years to come.
The legend of the Jersey Devil is also very similar to a variety of other legends about creatures whose existence no one can quite prove (sea monsters, witch tales, the Boogey Monster, etc.) It would be very easy to take the above factors and combine them with some already known legends in order to make a new legend that would provide entertainment for the citizens of New Jersey. This is a tale that is told over and over, especially to kids; it could simply be another form of a ghost story or legend that adults would tell kids to scare them at camp or give them something to talk about.
Finally, the legend of the New Jersey Devil gives the state an additional amount of pride. People in America tend to generally be very proud of where they come from and consistently look for ways to identify themselves. The story of the Devil gives New Jersey citizens something interesting to tell people from out of state, and also gives them an additionally sense of identity and pride.