The first Zoanoids (獣化兵, Zoanoids) were created by the Uranus, approximately 110,000 years ago, as the final outcome of their bio-weapons development program. It is unknown if they were always a design goal, or a modification of the human form that was decided upon later. The latter seems likely, since not all 'original' humans possessed the ability to take on a Zoanoid battleform naturally; they had to be processed in order to gain this ability. Only a minority of mankind had been 'zoaformed'. The Uranus were said to be highly pleased with their Zoanoid creations, but after the Guyver-Zero incident, nevertheless abandoned them and attempted to destroy them.
However mankind survived thanks to Archanfel and the Zoanoids, now without a leader, intermingled with the rest of mankind. While their blood thinned out, the Zoanoid genes would resurface from time to time, leading to legends of monsters and demons. Finally, about 400 years before the present, Archanfel re-awoke and created Chronos, and eventually Zoanoid production began again (although the mass processing of humans into Zoanoids seems to be recent development).
After X-day, becoming a Zoanoid was actively promoted by the new government, offering tax incentives as well as the other benefits that comes with being zoaformed: Zoanoids are naturally stronger and more able than the average person, don't get sick and have the ability to take on a super-powerful battleform which, in an emergency such as a roadside accident, can be extremely useful. Few people realize that Zoanoids have one more trait: they are completely subject to a Zoalord. They obey the telepathic commands of the God Generals without question, even across great distances. The horrific consequences of this became apparent when thousands of ordinary, but processed, people got up and walked away, to merge with, and die with, Cabraal Khan.
It appears that a Zoanoid can pass on their ability to transform to any offspring they produce; if only pure Zoanoids were to interbreed, processing might no longer be necessary. Oddly enough, no female Zoanoids - or rather, women who can take on a Zoanoid battle form - have ever been seen.
The actual, exact process that turns an ordinary human being into a Zoanoid is not known; it has been explained as subjecting the DNA of the subject to an array of chemical compounds which cause a rapid reshuffling of the genetic code, 'releasing' information which was already there, but dormant. Needless to say, this is a sort of hit-and-miss process; Commander Guyot quoted that "a good majority" of the subjects die during the procedure. He was not a specialist, however, and given that some people who were processed would be immediately missed if they "disappeared" (Such as White House staff members, or the prime minister of Japan), it must have been possible to ensure the subject would survive. Of course, the intense research performed by Chronos' scientists means things are learned with every processing that is performed, so it may be assumed the survival rate is higher - especially after processing became voluntary, rather than compulsory.
Processing usually takes a day or so on average (Although far briefer, and longer periods are possible); during this time, the subject is suspended inside a tank filled with amniotic and apparently hyperoxidated fluid (meaning, it can be breathed) and hooked up to feeding and monitoring cables. Interestingly, it is possible to prematurely interrupt processing, while the subject still is capable of taking a Zoanoid battleform; however, this will dramatically reduce their life span. For instance, when Genzo Makishima was processed into Enzyme-I, he estimated his remaining life span at a week, while the Enzyme-II's commander Guyot deployed died within an hour. What type of Zoanoid a subject becomes can apparently be set to an extent; some types are more 'common' in the population, and can easily be mass-produced - examples are Gregole, Vamore and Ramotith. It is apparently possible to turn any human subject into a Ramotith.
Whether or not a human has been processed can usually be determined through genetic testing, as noticeable changes have occurred in the DNA; some Zoanoid types, however, have a genome so like a human it's indistinguishable from a normal person's.
A Zoanoid battleform is radically different from a human body in many ways, while usually at least semi-humanoid. Many Zoanoids have a forward-leaning posture, with naturally bowed legs and noticeably elongated arms. They have no visible genitals or other gender characteristics, nor, it seems, excretory organs. The battleform is entirely geared towards combat, with no regard for other activities, and Zoanoids do not appear to eat. Their physical strength is far superior. While, for instance, Gregole is about eight feet tall and weighs about three hundred pounds, he is fifteen times as strong as the average human being. Muscle and bone structure are far superior to a human's, and the shape of the skeleton is also optimized for strength. In addition to increased strength, many Zoanoids sport armor - either flexible or rigid, or varying between the two - that is at least bullet proof, or even artillery-proof. Some Zoanoids are equipped with weapons beyond strength, claws and fangs: venom, acid, supercooled nitrogen or even laser weapons. The change is not merely physical: the brain also changes, causing the battle form to also feel like fighting. Zoanoids are all, and always, warriors.
Many Zoanoids resemble existing animals to some extent, usually mammals, birds, reptiles or arthropods. Others, however, appear bizarre and outlandish, with no relation to any known living thing.
When a Zoanoid dies, whether in human or battle form, his body will disintegrate with alarming rapidity; essentially, this is the same process that allows them to transform from one form to another.
Zoanoids of this type are engineered for melee combat. They are immensely strong and typically well armored, but usually have little in the way of special powers or bio-weaponry. The vast majority of Zoanoids are Power types (筋力増幅型, Kinryoku Zōfuku-Gata), bred to sweep into combat and crush everything in their path.
Zoanoids of this type are engineered to serve as living artillery, providing ranged support with bio-organic ranged weaponry, including bio-lasers, heat rays, and organic missiles. Bio-Blasters (生体熱線砲装備型, Seitai Nessen Hōsōbi-Gata) tend to be bulkier, slower and less agile than other variants of Zoanoid, as they are intended to stay at the rear of the force while Power type Zoanoids enter the thick of the fray.
Aqua-Type (水中型, Suichū-Gata) are rare Zoanoids that are optimized for sub-aquatic combat and are rarely seen outside of the watery environments they are created to fight in.
Scouts (斥候型, Sekkō-Gata) are relatively fragile, but quick moving, stealthy and intelligent. They are intended to advance ahead of Zoanoid forces to discern enemy locations, or optimized for infiltrating enemy positions before assuming Zoanoid form.
Airborne Early-Warning Type (早期警戒型, Sōki Keikai-Gata) have the engineered ability to fly, allowing them to provide aerial support for other Zoanoids and to attack opponents from the sky.
Hyper-Zoanoids (超獣化兵, Hyper-Zoanoids) were not envisioned by the Creators; they are an invention of Chronos, modified further from basic templates and elevated above the mass of the Zoanoids. They serve as intermediary commanders between Zoanoids and Zoalords. Hyper-Zoanoid creation is a recent phenomenon: the very first of their kind were produced only after the Guyver first appeared, although we may assume planning preceded it by years. Typically, they were special individuals even before they were processed - for instance, Oswald Lisker was about to be turned into a Hyper-Zoanoid at the time he became Guyver-II. While transforming a human into a Zoanoid is more or less a natural process and needs little direct overseeing, by contrast, every phase of the optimization of a Hyper-Zoanoid is carefully controlled. Because each Hyper-Zoanoid is carefully designed to optimize the Zoanoid potential, each Hyper-Zoanoid is therefore also unique; they can be re-created, but this is rarely done.
Hyper-Zoanoids physically stand apart from normal Zoanoids in that they have unique abilities, usually at least two separate 'power sets'. The most powerful Hyper-Zoanoids can be considered to be a match for the Guyver. Recently, more advanced Hyper-Zoanoids have appeared, that have been modified specifically to fight a Guyver, possessing qualities that negate several of its weapons (eg, reactive armor that can stop a vibro-blade and resist the vibrations of the sonic buster). Named Hyper-Zoanoids include:
- Empowered Zerbebuth
- Hyper-Zoanoid Team Five
Anti-Guyver Type (対ガイバー型, Tai Gaibaa Gata) were created for the singular purpose of combating Guyver units.
Sometimes, the Zoanoid creation process goes wrong; should the human survive this failed treatment, the result is an aberration known as a Lost Number (損種実験体, Lost Number). These mutant Zoanoids are one-of-a-kind freaks, impossible to replicate and implied to be functionally sterile by all means. Because of their mutated nature, Lost Numbers can vary widely in their capabilities. It's implied that Lost Numbers are results of experiments that ultimately discerned the methods for creating Hyper Zoanoids.
These Zoanoids do not have sufficient details available to classify them under any other category.
These Zoanoids are exclusive to the live-action Guyver films.