For years, Maine residents have reported occasional sightings of a mysterious creature with a bloodcurdling cry and glowing eyes. The beast is said to attack and kill pets, especially dogs. The animal is elusive, always evading attempts to track, capture, or kill it.

That is, apparently, until last month.

On Aug. 12, a woman in the town of Turner, Maine, found a strange dead animal. The creature appeared mostly blue; it had blue eyes, blue lips, and charcoal-colored fur. Though it had four legs and resembled a dog, Michelle O'Donnell, a neighbor, was certain that the creature was not a dog. Sensing that she had an amazing find—perhaps even the long-sought mystery beast—she took photos of it which were published in the local newspaper and posted online.

While flies swirled around the decaying carcass, controversy swirled around O'Donnell's photographs. [MSNBC.com has a photo of the creature.]

The "Maine Monster" was a media sensation, making international news and spawing speculation. While some claimed that the animal was unknown (or a "mutant hybrid"), others suspected it was just an unusual-looking dog. When Maine monster hunter Loren Coleman was shown a photo of the creature on Aug. 13, he stated, "This is a dog, probably a feral dog or a hybrid, but a dog." 

Other people even suggested that the creature might be the dreaded chupacabra of Latin American lore, the mysterious beast said to drain the blood of pets and livestock.

Finally a sample of the creature was sent to the University of Maine, where DNA analysis concluded that the animal's mother was from the Canis family. While the father's genetic link was not absolutely certain, it was likely also a Canis. According to University of Maine scientist Irv Kornfield, the beast "has all the indicators to link it to being from Canis, a dog."

Thus the matter was settled, for all but the most die-hard of believers. (In at least one case where a suspected chupacabra sample was tested, the results indicated that the animal was a mangy canine. The person who owned the beast insisted that the animal was not canine and that a dog specimen had mysteriously been switched for the actual sample he sent. Conspiracy theories never die.)

On the message boards at the monster-hunting Web site Cryptomundo.com, the mystery beast was a hot topic. Many posters commented that they were baffled by all the hype the creature received; after all, it was just a dog! Yet this is an excellent example of a typical lake monster or Bigfoot sighting: A person sees something he or she doesn't recognize, and concludes that the animal is an unknown creature. As this case clearly shows, just because a creature can’t be immediately identified does not mean that someone else (perhaps a zoologist, or a dog breeder) might not know exactly what the animal is.

The only difference is that in this case (unlike, say, Bigfoot or chupacabra) we actually have a carcass to positively identify. If this animal had just been glimpsed as it bounded into a wooded area and not caught (or later found dead), it would remain a mystery monster to be written up in future books on the unexplained.

The Maine Monster is an object lesson in the ways that people can "create" monsters because of misperceptions or logical fallacies. And what of the "real" Maine Monster, the one with the eerie cry and glowing eyes? Loren Coleman maintains that the long-sought creature still lurks in the forests: "I think there is a mystery beast out there in the woods around Turner." Until and unless it too is found, the stories and sightings will continue.

Benjamin Radford is managing editor of the Skeptical Inquirer magazine and co-author of "Lake Monster Mysteries."