Judging by movies and television, everyone loves a good zombie. The walking, or perhaps shambling, shuffling dead, or undead, if you prefer…. Things that look like human beings but aren’t, so you can beat the crap out of them without any pangs of conscience.

Having done a bit of reading on the topic, I have concluded that there are actually six distinctly different types of zombie.

First, there are those people who through either accident or malice, have been declared legally dead. We’re not talking about the brain dead, or those who have “died” on the operating table and have been resuscitated. No, these people have found their bureaucratic condition changed to “deceased”.

The archetype here is Lal Bihari, of Uttar Pradesh, India. Back in the mid 1970s, a greedy uncle of his went to a government office and bribed an official to have Bihari listed as dead in the records. The uncle was then able to “inherit” a particularly nice piece of farmland. In his efforts to get his “life” back, Bihari insulted judges and government officials, ran for public office, and found that his situation wasn’t that uncommon. Strangely, the only time where he wasn’t listed as “deceased” was when his wife tried to collect a government benefit for widows.

The second type is even more peculiar. There’s a neurological condition known as “Cotard’s Syndrome”. This apparently affects the part of the brain that governs a person’s “sense of self”. With this part damaged, the sufferer resolves the loss of identity by concluding that they are dead. It’s not fun. One stops doing things like basic hygiene (if you’re dead, what’s the point?) and can barely function in society. Never mind anything like holding down a job. It was first reported in the 1700s, as has popped up every now and then on medical TV dramas.

For the third type, we step just a little out of reality. “Philosophical zombies” (P-Zombies for short) are mental constructs used in discussions of the philosophy of mind. They are for all intents and purposes identical to a human being, but there’s no “soul”, “consciousness”, “sentience”, or what have you in them. Sort of a walking “Turing Test” in that these come up in arguments about what makes “humans” human. A close approximation to these P-Zombies might be non-player characters in a computer game.

Stepping further away from the Real World brings us to the traditional “zombi” of Haitian voodoo. Start with a person who is ill or weak, and use a combination of drugs and hypnosis to completely take over their will. You’ll get a person completely in your thrall (I’m probably simplifying this a great deal). Unable to act independently or even feel pain, zombi are typically used as slave labor for their  creator. The movie White Zombie shows this quite well. These zombies aren’t actually dead; they just act that way.

Our fifth type of zombie is the basic “revenant” – a corpse brought back to life. Usually this is at the instigation of an evil wizard or mad scientist (as in the movie Re-Animator). Such zombies can be very difficult to control.

Finally, there are the standard brain-munching, flesh-eating zombies that we all know and love. Their first appearance of note was in the movie Night of the Living Dead. Curiously, in that movie, George Romero never referred to them as “zombies”. It’s only popular culture that has given them the name.

I feel I must point out something having to do with this final type that people seem to overlook. In none of my research have I ever come across any indication that these undead ever heal. That ought to be a major factor in any outbreak. Think of all the little bumps, nicks, scrapes, and scratches you endure every day. Now think of all these zombies who don’t know enough to wash their hands or put on a bandage. Or watch their step to avoid ankle sprains and banged up knees. All those open sores and wounds, filled with bacteria and little insects that love feasting on human flesh, especially when there’s no pesky immune system to get in their way…. Heck, I’d be more worried about things like cholera and typhus than getting bitten by a zombie.

There’s a new type of “fast zombie” that has come onto the scene (see 28 Days Later). But since it’s not really clear if those suffering from this “Rage virus” are actually dead. I cannot yet classify them separately. They are too similar to the last type described above.