Idaho Mountain Lion Found With Full Set of Teeth in Its Forehead

— -- Warning: This contains a graphic image below.

A mountain lion found in Idaho is making animal biologists and wildlife officials scratch their heads in confusion as they try to understand what caused the abnormality in the creature.

On Dec. 30, a homeowner near Preston, Idaho alerted hunters in the area of a mountain lion that had attacked his pet dog. The lion ran off, but a hunter was able to find it using its tracks and a hound dog, Jennifer Jackson, a regional conservation educator with the Idaho Fish and Game, told ABC News today.

The hunter killed the young male lion near the Utah border, but a photo taken of it, shows a full set of teeth and whiskers growing out of its fur-covered tissue on the left side of its forehead. The sight has left scientists baffled.

“I’ve never seen anything like that before in a mountain lion," said Amy Rodrigues, a biologist with the Mountain Lion Foundation who has been studying mountain lions for more than eight years.

The Idaho Fish and Game, which issued the hunting license and tag for the hunter who harvested, or killed the lion, said there are two possible reasons for the biological mystery. The first explanation is that the teeth could be the remnants of a twin lion that died in the womb, and the teeth were absorbed by the other fetus.

The second explanation is that the bizarre deformity could be a product of a teratoma tumor, in which the tumor is composed of tissue where teeth and hair can develop. "Teratoma" is greek for "monster," and it is a rare condition for both animals and humans. In humans, the tumor can even grow fingers and toes, Jackson said.

Although Rodrigues said the deformity "looks painful," its possible that the lion didn't feel pain because the teeth in its head didn't affect its movements too much, allowing it to survive until adulthood. Animals with mutations typically don't survive long in the wild, she said.

"It would have been nice to discover it while it was still alive, to be able to do some research and track it to see if the growth really did inhibit it," Rodrigues said.

The hunter who killed the lion turned its body over to the Idaho Fish and Game for examination temporarily, which is required by law. The organization has requested that the body be released for further study by veterinarians to better understand what caused the deformity. The hunter has declined to be interviewed, and the Idaho Fish and Game is unable to disclose the names of people who have purchased hunting licenses and tags.

It's legal to hunt mountain lions in the state of Idaho, but they can only be pursued during certain seasons and areas, and hunters are required to have the proper license and tags. The big cats typically prey on deer, elk, moose, mountain goats, bighorn sheep but will also go after other small mammals like raccoons, rabbits and household pets. They will occasionally prey on livestock as well and are well adept at avoiding humans, Rodrigues said.