There is a lot of confusion surrounding the term "zombies," mostly because there are a range of zombie subcategories which vary greatly from one to the next. There a two common factors linking zombies from all subgroups. (A) zombies possess a limited ability to think, which affects their speed (slowing their movements considerably) and preventing them from advanced problem solving. (B) zombies seem to focus only on a need to feed, and often seek out living humans to satisfy this need. There are at least 4 different known subgroups of zombies, each determined by the method of application:
(1) CHEMICAL - Zombies created by the application of chemicals, medicines, herbs or potions. This method can be used on a living subject to reduce him to a mindless servant or, more often, to create a destructive menace.
(2) RITUAL - Creation of zombies by religious ritual practice. Through Ritual, one can re-animate a corpse. Though ritual is often used to re-animate a single corpse, it is possible for a skilled practicioner to raise an army of the undead during one ritual. Ritual zombies are often the most decayed of any subgroup. Other groups are created while the subject is alive (or soon after). Though this makes ritual zombies easier to destroy than other types, they often make up for this in sheer numbers.
(3) VIRAL - The viral method is the creation of a zombie by blood-bourne infection by another zombie, usually from bite wounds or from direct contact (such as injection) of zombie blood into the circulatory system. While one zombie may have been created through chemical or ritual, it may infect a living person virally from a bite or scratch.
(4) SPONTANEOUS - Zombies said to have been created spontaneously are those that lack any of the above three applications. Zombies in this categories are sometimes reanimated by a powerful emotion, such as hatred or revenge. Revenants, for example, are the re-animated corpses of someone who is not ready to let go, and often feels as though he has a mission to complete (even after death). These can be the most difficult to prevent, simply because their is no external agent creating this type of zombie.
HOW TO KILL A ZOMBIE: