Zombies are a product of our modern collective conscience. This archetype is so prevalent currently, with the popular AMC series Walking Dead. (I love that gory show, although I am behind in viewing the second season.) We even have an example of the myth coming to life and the 6 o'clock news with the Miami man who viciously attacked and chewed on the face of an older homeless man. Tests showed that he only had marijuana in his system. Was he operating on a mental level that allowed the zombie archetype to express itself through him? We will probably never know why he preformed such a horrific crime.
Originally zombies came from an ancient African voodoo belief that a corpse could be put under the spell of a sorcerer who reanimate it and control it like a mindless automation. many say the practice still goes on it Haiti today. George Romero gave Zombies a scarier twist in "Night of the Living Dead" (1968) by retaining the "rising from the grave" element but losing the idea of the controlling sorcerer. Romero also introduced the idea of a "bite" turning people into zombies and that there was no controlling force or reason/explanation for their existence. That gave the archetype a modern twist and power.
So we have to ask ourselves what are zombies trying to tell us? What is our "collective unconscious" trying to tell us, with so many zombie examples around us? It seems to me that zombies are a symbol for the great indifference of our population, to our politics, to our gas prices, to our wars, to our everyday automaton 9 to 5 life. We are the protagonists but we are also the zombies. Our deepest unconscious minds are telling us to "wake up."