By now most of you probably have seen pictures of Frank and Louie, who, at age 12, is the oldest-living two-faced cat. They (he?) have two mouths, although only one is used for eating, and one brain. Although Frank and Louie have three eyes, only two are operational, and they seem to work just fine.
The disorder is called diprosopus, or craniofacial duplication, a rare condition that causes duplication of the face and sometimes the cerebral frontal lobes. Felines with this condition are often called Janus cats after the Roman god who had two faces.
Frank and Louie's long life has been attributed to the care and love from his (their?) owner, who so far has only been identified as a woman named Marty who reportedly lives in Massachusetts and saved the cat from being euthanized when he was brought into the veterinary medicine school where she worked.
Most cats with the condition don't live long due to related health issues, but Frank and Louie have beaten the odds and now have a place in the 2012 Guinness World Records book.