The original zombie-Voodoo

there are zombies
however, there are actually very very few of them
they are created in part by a poisoned powder 
they are created in part by the effects of the culture
zombies are created when a person first falls into a death-like trance which is both drug and culturally induced
then is revived and kept under the control of the houngan by the use of other drugs
zombies are created by Voodoo priests who are members of the Bizango secret societies
Bizango societies constitute a totally secret and hidden other government beneath the surface of Haitian society
zombification is not random nor for profit or personal vendetta
zombification is the ultimate punishment to someone who has seriously violated the law of the Bizango society

Zombie (Haitian Creole: zonbi; North Mbundu: nzumbe) is a term used to describe a hypnotized person bereft of consciousness and self-awareness, yet ambulant and able to respond to surrounding stimuli. Of voodoo (Vodun) origin, the word initially referred to a curse cast by sorcerers (or bokors) allowing them to take control of a person's mind, therefore affecting his or her actions. However, due to significant influence of Haitian Vodou and New Orleans Voodoo on witchcraft mythology, this meaning soon morphed into that of a human corpse mysteriously reanimated to serve the undead. Since the late 19th century, zombies have acquired notable popularity, especially in North American and European folklore.

(Just in case anybody wasnt aware of the origins of real life zombies, as part of the Haitian voodoo culture...)