4 Legged Goat
A goat in Croatia was born with 8 legs, due to a mutation. The goat was not only special because of the double amount if legs it had, but also because it had male, as well as female reproduction organs. Veterinarians found out, that the mutation developed out of remnants of his underdeveloped twin. Unfortunately the special goat only survived one week.
Duck with 4 Legs
A very similar case was found in the year of 2014 in Louisiana, USA. A duck was born with 4 legs, but in contrary to most other mutated animals, the duck survived and lived a normal life. The duck got so famous, that he even got his own social media pages. 2 or 4 legs, this duck is super cute.