The animal was found by Erika Constantine, who was out walking her pooch and whipped out her camera to capture some footage.
The 25-year-old said she was walking in an area called Sunrise Park when she made the discovery.
"I take my dog, River, there very frequently," she explained.
"We were just strolling, and she went up to it. I saw her picking at something with her nose and that's what made me walk over there because she only does that if something is dead, or if something interesting to her is over there."
The animal is mainly bone, with a skeletal fin or rib cage poking out and a few teeth remaining.
Erika added: "I honestly did not know what it was. It was the size of a small dog, but the structure of the whole thing suggests it's definitely not a dog.
"I have lived here for about five years and I have never come across something like this."
Unable to distinguish the creature, Erika shared images of the animal online to try and get some answers, but it seems as though everyone is as stumped as she is.
"I thought somebody would be like, 'Oh, it's like a seal,' and then I would go about my day, but it stumped a lot of people," she said.
"There are so many theories as to what it is. The cops said it was a possum - it's definitely not a possum. People were saying it's a dog, people were saying it's an iguana.
"Somebody said it was a bobcat which was interesting because they do have similar rib cages."
Among the more... erm... 'unusual' guesses were claims it was the mythical Chupacabra, a fictional beast said to drain livestock of their blood.
In her quest to get to the bottom of the mystery, Erika has contacted a professor at the College of Charleston but hasn't had a response just yet.
Erika has her own slightly-off-the-wall theory, too, as she reckons it could have come from a nearby restricted island, which is inhabited by monkeys and off-limits to human visitors.
"It's technically called Morgan Island but it's nicknamed Monkey Island," she said.
"It's not inhabited by humans, it's all monkeys. That's where all the monkeys that the government tested on live.
"I think one of the monkeys from Monkey Island unfortunately might have got swept up in a current, the rip tide or whatever and then it made its way to Charleston.
"It wouldn't really be the first time, my friend actually found a monkey fossil on the beach a while back, so I think it just kind of got washed up here."
The monkeys belong to National Institute of Allergy and Infectious Diseases, though the institute says it carries out no disease research on the island, beyond monitoring the monkeys.
Whatever it is, Erika is pleased with her discover, adding: "I think it was awesome. I love weird stuff like this.
"I was super excited to figure out what it was and get other people's opinions on it.
"Whenever I go to the beach, I always keep my eyes peeled for something cool because you never know what's going to wash up."
Featured Image Credit: Penn News
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