Esther Inglis-Arkell at i09.com wrote a fairly convincing article about how the rabies virus is probably the source of all of the zombie legends. It turns out there are two types of rabies: dumb rabies and furious rabies. It’s furious rabies that is your classic rabies disease. People infected with the rabies virus lose lucidity, become aggressive, and can become physically violent. The virus is transmitted through saliva, which is one of the basic themes in zombie legends; the zombies will try to bite you. Luckily, in most industrialized cultures rabies is easily treatable, but worldwide rabies still claims 60,000 lives per year. But be careful–the zombie apocalypse will take more than that!