8. Mountain Lion with Extra Set of Teeth
This toothy beast was killed in this past December in Idaho, near the Utah border. The mountain lion had attacked a pet dog leading authorities at the Department of Fish and Game to track down the cat.
When they found him, they discovered he had an extra set of teeth growing out the back of his head! This is thought to be either the result of a teratoma tumor, which leads to growth of extra teeth, and other extra features, or the absorption of its twin in the womb. Regardless of how, this is one cat I do not want to meet while hiking!