A mountain lion hunted down in the Idaho wilderness was found to be sprouting teeth from its forehead, a weird find that left wildlife biologists with a couple of theories. The young cougar was legally tracked and killed in late December after it attacked a dog near the southeastern town of Preston, the state Department of Fish and Game reported. The hunter reported his kill, as he was required to do, and a state conservation officer showed up to confirm the hunter’s license and pull a tooth from the animal for age analysis, the department stated. The defect was easy to see. “The mountain lion had an unusual deformity,” the agency noted. “Fully formed teeth and what appears to be small whiskers were growing out of hard fur-covered tissue on the left side of the animal’s forehead.” Wildlife experts had two possible explanations for the abnormality: The teeth may be the remnants of a conjoined twin that died in the womb and was absorbed into the other fetus. The deformity may be a rare teratoma tumor—“tissue from which teeth, hair and even fingers and toes can develop,” Fish and Game stated. “Biologists from the southeast region of Idaho Fish and Game have never seen anything like this particular deformity before,” the agency added. The whereabouts of the carcass are unclear because the hunter was permitted to keep the animal. The Western United States, from rural Idaho to metropolitan Los Angeles, is home to an estimated 30,000 mountain lions.