In many stories about the Devil, a pet helps him with his mischief, like a witch's familiar. After all, being the ultimate evil in the world must be tiring, lonely work. Or perhaps the Devil is just a misunderstood character. Whichever the case may be, sometimes he needs the comfort and help that only a pet can bring. I originally wanted this list to be all about the Devil's cat, but I could only find a couple of examples, so I expanded the parameters to include other pets.