You may think that zombies only exsist in horror films, but there really are animals that return from the dead. They may look dead but they really are alive. Find out who's the best as we count down the top 10 examples of the living dead. While some animals sleep through winter, the best hibernators can sleep for well over a century! Discover how easy it is for some animals to return from the grave when zombies are taken to the Most Extreme.