Zombies are very much real in Voodoo!
A Boker uses a powder (which has highly toxic components) and gives it to the person they wish to be a zombie.
The person then appears to be dead, as this poison lowers the heartrate where it can't be detected, pupils dilate and are not reactive to light, they are paralyzed unable to move or speak.
The family buries their loved one.
Then the Boker exhumes them as the poison wears off.
The victim appears mindless, disoriented, has trouble with simple functions, and appears mindless.
Ta-Da you have a Zombie.
Being the victim was raised from the dead by the Boker, he's willing to do as he's asked.
In my option it's all about belief. The family fears and/or respects the Bokor and Voodoo, so it's more or less mind control.
However, a Bokor claims he controls the entire situation using spirits.
But none the less, the Hollywood Zombie was based on this practice. So yes, making a Zombie is possible. However, if you don't know what your doing (and sometimes even if you do, the victim will die. It's a very dangerous thing, and shouldn't be done.
If I'm not mistaken in zombie is actually spelled zombi and means "spirit of the dead" in that practice.