Bigfoot and the Loch Ness Monster rank as the top two best-known monsters in the world, but since its 1995 debut, El Chupacabra has made a Justin Bieber-like ascension to No. 3 on the charts. The relative newcomer to the monster world is the go-to culprit for weird livestock deaths and creates a massive media stir whenever it's "sighted." It even has a fan club on Facebook.

That could all end, now that Benjamin Radford, author of several books on monsters and paranormal phenomena, managing editor of the journal The Skeptical Inquirer and LiveScience columnist, has released what he says to be definitive proof that El Chupacabra is not real; it's not even a hoax, he said, but rather a leftover memory of a science- fiction film.

Stories of El Chupacabra first surfaced in March 1995 in Puerto Rico, Radford said, when dead, blood-drained goats began showing up (El Chupacabra translates to "goat sucker"). That August, a newspaper printed an eyewitness description of a bipedal creature, 4 to 5 feet tall with spikes down its back, long, thin arms and legs, and an alienlike oblong head with red or black eyes. That depiction became associated with El Chupacabra, and it reports of similar creatures began popping up throughout the Caribbean, in Latin America, Mexico and Florida.

The frenzy had died down slightly by 2000, but picked back up in 2004 when something began attacking livestock in Texas. A farmer shot one of the offenders, and later more alleged El Chupacabra carcasses turned up. They looked nothing like the Puerto Rico original, though, and DNA tests later revealed that they were actually coyotes with a severe case of mange.

On top of the sudden change in appearance—a hairless, snarly-looking four-legged creature is the popular depiction in Texas—these coyotes didn't even act like El Chupacabra. "When you did a necropsy of the chickens and goats that they attacked, they all had normal blood levels," Radford told Life's Little Mysteries. "They were not, in fact, vampirized."

"By the mid-2000s, anything weird was being called El Chupacabra," he said. "Mangy coyotes. Dead raccoons. Even a dried fish in New Mexico, which looks nothing like El Chupacabra." And yet the myth continued to gain momentum, so Radford, who has researched El Chupacabra and other strange sightings around the world for years, decided to cut it off at the head and set off to Puerto Rico to trace the beast back to its fictional roots. (Disclosure: Radford is a contributing writer to Life's Little Mysteries and columnist for its sister site, LiveScience.)

Mistaken identity

Radford dug through every El Chupacabra mention and traced the physical description of the monster to a single event in the second week of August 1995, when a sketch from an eyewitness named Madelyne Tolentino ran in a Puerto Rican newspaper. Locals immediately tagged the alien-looking animal as El Chupacabra.

The creature, Radford noticed, shared a strong resemblance to the alien/human hybrid in the 1995 sci-fi thriller "Species." When he spoke to Tolentino, he asked her if the thing that she saw could have been inspired by the film. Indeed, she had seen the movie in the weeks prior to making her description.

"You can make a direct connection between the film hitting theaters, her seeing the creature in the film, seeing it in the street, making the report and entering the public conscious," Radford said.

Soon after, reports of nearly identical creatures began appearing throughout Latin America. But these can be dismissed, Radford says, because they're all based on Tolentino's Hollywood-inspired monster.

"What I've tried to do is take the whole El Chupacabra enchilada and break it into small mysteries and then solve those mysteries," Radford said. "There's no place else for those mysteries to hide now. If I haven't solved every piece of it, then I don't know what I'm missing. It's all there."

"That said, if next month or next year somebody finds El Chupacabra that's sucking blood from animals, I'm happy to eat my crow and add a chapter to the book."

The last word

Even if you're not convinced by DNA evidence or Radford's research, simple logic should help you realize that El Chupacabra just doesn't exist.

For one thing, it would take a couple hundred to a few thousand of the creatures to keep the species alive. If each of those animals is five feet tall and weighs around 100 pounds, it would be pretty difficult for there to be no confirmed sightings or fossils, particularly on an island as small and as densely populated as Puerto Rico.

For another, even if the beasts managed to hide, they'd still need a lot of food, and if they are actually vampires, then you'd expect to find a lot more blood-drained carcasses.

If true believers have one complaint against Radford's work, he expects them to say that it's implausible that Tolentino saw something that doesn't exist. Radford, who has a degree in psychology, chalks that up to confabulation, a common scenario in which people simply confuse the fictional and real worlds. [10 Urban Legends Debunked]

"The question then becomes which is more likely, the astronomical chance that this creature looks exactly like the one from 'Species,' or that the film is just where she got the depiction?" Radford said.

So why does the myth persist? Radford says it's the result of a perfect storm of urban legend-brewing conditions. El Chupacabra was one of the first mythical beasts discovered in the Internet age, and its image and story spread around the world — and especially to Spanish-speaking countries — in a matter of weeks. It also gained the early support of UFO enthusiasts, who latched onto the idea that the creature was alien, or an alien's pet, as well as the conspiracy/cover-up angle often associated with forensic analyses of the "beast."

Radford has another theory: "The thing about myths is that people want to believe in things," he said. "I suppose that, in a perverse way, there's something comforting in that there's this vampiric monster that doesn't attack humans."

This article was provided by Life's Little Mysteries, a sister site to LiveScience.