Like skeletons, zombies are corpses animated by magic. However, they also possess an animalistic instinct to attack and feed which makes them harder to control, yet somewhat easier to predict. Beyond the fact of their animation, zombies are indistinguishable from mundane corpses, and are as varied in their appearance as that morbid panoply allows.
Dependent on the manner of death, level of preservation, and amount of time elapsed between expiration and reanimation, zombies can be horribly bloated with noxious gases, crawling with scavengers, oozing with putrefaction, withered and near-skeletal, or they may display any number of grotesque physiological traits that go along with the grim process of decay. The only essential commonality is that there must be some level of flesh covering the bones in order for the zombie to haul itself around for, while there is magic holding them together to a point, it is limited compared to that which knits together other types of undead, such as skeletons.
As zombies (and ghosts) are probably the most widespread varieties of undead, and therefore most likely to be encountered by a layman, there is not so much superstition surrounding them as practical solutions to deter and dispatch them. All cultures must deal with their dead respectfully, but it can be unwise to assume they will simply stay dead. In rural locations, inhabitants will typically bury their dead a way out of the village boundary and will dig a moat between the gravesite and the community. Any risen dead, with their propensity to run in a straight line towards living victims, will suffer a sharp drop and remain trapped, to be dispatched at leisure.
In larger centers of civilization, which have grown to overtake and surround formerly outlying burial sites, inhabitants often erect strong fences and employ guards to ensure the contents of their graveyards don’t go wandering. Similarly, it has been suggested by some that the nobility’s inclination towards grand mausoleums of stone to inter their dead is as much for practicality as it is to be a show of grandeur. A large stone structure, barred with iron, is as difficult to break out of as it is to break in: anything to avoid the indignity of seeing some revered ancestor shambling about, gnawing on the populace.
zombies are potentially one of the least useful. Truly mindless, they will obey the will of the one who raised them to the best of their abilities but, given the extreme limits on their intelligence, options are limited. For this reason, zombies are generally only deliberately created by apprentice necromancers, or as fodder in the undead hordes of those more powerful. However, their creation is also a common side effect of powerful necromantic rituals bleeding into the surrounding area.
The magic used to raise a zombie reanimates the brain with limited functionality, allowing it to control the body’s motor functions. While they are no stronger than their living counterpart, their inability to feel pain, and therefore the stresses and strains of pushing themselves beyond reasonable limits, allows even the most unremarkable zombie to accomplish feats of strength and endurance on par with a highly-trained warrior.
While enough damage to the limbs can stop a zombie from moving, a limbless zombie will still writhe and snap at anything it can reach. The only way to truly destroy a zombie for good is by removing the head or destroying the brain.
While animated by magic, and able to shrug off blows which would kill or incapacitate a creature capable of feeling, zombies are still corpses and, as such, still rot. The dark energies animating them will hold them together up to a point but, should so much rotting flesh slough off the zombie’s form that it is unable to move, the magic is powerless to compel it otherwise. For this reason, zombies are more or less of a lingering threat depending on the environment; the natural preservative effects of cold or dry heat can keep the undead in a viable state almost indefinitely. On the other hand, zombies raised in more tropical latitudes will rot away very quickly, though their pervasive stench may linger for some time. Also, while frozen temperatures can certainly delay the process of decay, extreme cold can freeze the zombies entirely. In environments such as these, even if the creature is able to move, the dry, frozen skin and muscle will be frostbitten and brittle, and will soon flake away.
Zombies are extremely limited in their interactions with other creatures, and entirely devoid of individual personality. They are sluggish to respond to stimuli, and easy to feint and mislead. Zombies are able to undertake tasks on the orders of their master, but will always go about them in the simplest and most literal way, and generally with a large amount of collateral damage, unless given explicit orders. Any other factors will be ignored while a zombie carries out its task, even factors which would endanger or destroy it.
Zombies lack the intelligence for even the basic tactics shown by animals. They will attack whatever living being is closest to them, though they do have a preference for humanoid prey. Engaged by multiple foes, a zombie will flail, attacking at random rather than focusing on a single target.
Zombies have no sense of self-preservation, so will attempt the shortest path to a target, even if it means suffering deadly hazards which would be obvious to any other creature. Powerful necromancers can use this to their advantage; given enough zombies, almost any barrier becomes surmountable. Dozens of zombies can clog the mechanism of a trap, hundreds can dam an inconvenient river, and thousands might create a mound of bodies high enough to create a serviceable siege ramp.
A less common form of zombie, plague-born are the result of a virulent contagion animating the corpses of the infected, rather than necromantic ritual. Having been transformed into zombies at the point of death, they tend to be less advanced in their level of decay than other zombies. Indeed, were it not for their unnatural movements, feral bloodlust and, in most cases, horrific wounds, many would be indistinguishable from the living (albeit those living with a terrible illness).
Originating from a necromantic disease rather than being raised, plague-born have no master to serve and will attack any living being they come across. They are more reactive to external stimuli, and will flock towards bright lights or loud noises, often congregating in great swarms, descending on the source like crows on a carcass.
Given their unique and difficult-to-replicate nature, it is theorised that all plague-born originate from a single source. Whether a botched attempt to raise a common zombie or a vindictive curse, we may never know and, given their frighteningly rapid proliferation, it is likely whoever was responsible is in no position to say.
The disease is transmitted through contact with infected blood. Bites are the most common – and most dangerous – form of exposure, though any form of contact with contaminated blood carries a risk. Those exposed contract a horrible disease which, upon their death, animates their corpse as a zombie. Should a plague-born remain animated for enough time (usually a few weeks to a few months), the disease ferments into a more virulent strain; those infected by one of these ‘plague-hosts’ reanimate with the ability to further spread the disease.
The disease acts quickly; depending on where a victim is bitten, death and subsequent transformation can take place in a matter of minutes, though the uncommonly resilient may last a day or longer. Fever and convulsions are rapidly followed by vomiting blood and an insatiable hunger and, finally, the afflicted slips into oblivion, reanimating within minutes.
Spreading as a contagion from host to host, plague-born zombies are more dangerous the more potential victims surround them. They are drawn to centers of civilisation as their best food source and means of proliferation. When there is no obvious food source around, plague-born wander, directionless, until they find one, or until they disintegrate entirely. Very rarely, a plague-born might show some preference for locations and stimuli important to who it was in life. One might be drawn to wander the same streets it did in life, or appear fascinated by tools or clothing relevant to its former trade. While this might lure the unwary to hope that some remnant of a former loved one remains in the creature, the phenomenon is simply due to rote action in life (a process similar to ‘bone memory’ in skeletons), and any seeming interest is quickly ignored, should living prey present itself.
Plague-born behave in a similar manner to zombies left to their own devices, simply at a much faster pace, appearing jittery and unstable. They take orders far less readily than their sluggish kin, with any instructions constantly battling with the urge to bite and feed (and losing, more often than not).
Like their common cousins, plague-born attack mindlessly, though they have a glimmer of animal cunning; at least enough to prefer attacking those who face an immediate threat to those who do not. They swarm towards intense stimuli, so any effect which produces loud noises or bright lights is sure to attract plague-born in the immediate area, and perhaps even those from further afield.