Halloween's Top 10 Scary Creatures

They're creepy and they're kooky, mysterious and spooky. But Halloween's creepiest creature customs didn't appear out of thin air, not even the ghosts. Many of them once instilled real fear in medieval towns, when folklore reigned supreme and getting freaked out came easy. Here we offer up some real science and history of the scary stars of Oct. 31. -- Heather Whipps