Super Mutant

Super mutants or meta-humans are mutated humans, products of infection by the Forced Evolutionary Virus, or F.E.V. They are much taller, bulkier and muscular than pure strain humans, have (mostly) green, gray, or yellowish skin, are immune to disease and radiation, and are gifted with superhuman strength and endurance. Although they are completely sterile, the rapid regeneration of their cells caused by FEV makes them biologically immortal (but not immune to death from injury, of course).

There are two different known sources of super mutants in the Fallout universe - Mariposa Military Base in the Core Region (on the West Coast) and Vault 87 in the Capital Wasteland (on the East Coast). The two populations have separate histories and origins, and are yet to interact with each other.

Biology
Average super mutants stand approximately 10.5 feet (3.2 meters) tall (although they typically stand with hunched backs that reduce them to about 8 feet, or 2.4 meters) and weigh around 800 pounds (360 kg), possibly even more. Their skin color is predominately gray with tints of green, although some mutants with other skin colors also exist. Their skin is extremely tough, and their muscle and bone structure are enhanced well beyond the human norm.

Super mutant cells undergo cellular division at a greatly increased rate. Mitosis occurs at a rate 15% quicker than that found in pure strain humans. A super mutant's cellular structure is said to be highly similar to normal humans. Super mutant DNA strands are nearly flawless, with all of the recessive genes that produce many of the most common ailments like diabetes, cancer and cardiovascular disease eradicated from the genome. Those recessive genes which are commonly found in humans have been manipulated in such a way by the infection of the FEV virus as to bring about the best possible combination of genetic traits. A super mutant's RNA structure was also altered by the virus to produce more rapid transcription, resulting in the enhanced regenerative capacities of the mutated form.

The mutation produced by the FEV in this case has some severe side effects. Chief among them is sterility. As the gametes of the reproductive system consist of 'half-cells' comprising only 23 of the normal 46 chromosomes, they are perceived as 'damaged' cells by the FEV's integrated genetic sequences, which "repairs" them by restoring the missing chromosomes, which essentially renders the mutants sterile since their gametes lose the ability to recombine with other sex cells in sexual reproduction. super mutants are unable to reproduce with any human, whether they are pure strain or also mutated. Other side effects of this form of FEV infection include an alteration of the pigment cells of the epidermis. While the super mutants originating from Mariposa are sterile, they do not lose their sexual organs or secondary sexual characterics of their original gender. In contrast, the Vault 87 strain of FEV causes the subjects to lose most of their visible secondary sexual characteristics. Interestingly enough, Capital Wasteland Super Mutants lack toes. (As seen on the subjects floating in tanks of fluid at Raven Rock.)

While they will not die due to the normal effects of aging, super mutants are prone to senility, leading to tendencies to engage in near-psychotic, aggressive attacks against other humans and other creatures. As super mutants created by the modified strain of FEV as part of the Evolutionary Experimentation Program in the Capital Wasteland age, they grow consistently larger and stronger, eventually reaching heights of up to 2 stories.

West Coast mutants
The Mariposa super mutants are a variety of super mutants common on the West Coast and in the Midwest that originated from the Mariposa Military Base in California. While some of them can be rather stupid, in general they are more intelligent and civilized than their distant Vault 87 cousins in the Capital Wasteland.

History
Super mutants were first created on the West Coast by Richard Grey, also known as "The Master", who led the first human survivor expedition to Mariposa Military Base in 2102. When the expedition was attacked by the base's automated security robots, he was dipped in a vat filled with mature FEV virus in solution, and managed to crawl out. The FEV was initially meant to be injected into humans, but Grey soon found out that direct physical contact with its nutritional medium worked just as well. He began to mutate in horrible ways, turning into a fleshy, tentacled blob of sentient matter. The mutated form of Grey developed psychic powers, which were enhanced by consuming living minds to expand his own psionic strength. Slowly, as other wanderers from the Wasteland made it into the Mariposa Base themselves, Grey started performing his own experiments with the FEV. Grey — who now called himself "the Master" — lamented the needless destruction of human society caused by the Great War. In his warped state, he decided that he would have to force humanity to evolve beyond its innately destructive tendencies. If everyone could be as perfect as his evolutionarily advanced super mutants, the Master reasoned, there would be no more conflict in the world. Those who would not evolve would be forcibly sterilized and allowed to live out their lives in peace, though without the ability to pass on their imperfections to the next generation. Around the year 2155, the Master began seeking out uncontaminated, pure strain humans with which to create new mutants and build the super mutant army he required to carry his plans to fruition.

In 2162, a person known to history only as the Vault Dweller destroyed the Master's mutant army by causing an explosion in the FEV vats at Mariposa, which collapsed the entire base, after which he proceeded to The Cathedral in the ruins of Los Angeles and killed the Master. Without the leadership of their creator and his lieutenant, the mutants divided into at least three factions. Some decided to leave California and find a place for themselves somewhere in the East, while a second faction wanted to continue the Master's work and dominate the Core Region once again. A third faction remained in the Core Region and tried to make peace with the Wasteland's humans, and worked together with them to rebuild the world after the Great War. Broken Hills is the most notable example of a settlement where humans and super mutants have learned to live together in peace.

The faction of super mutants that traveled eastwards eventually settled in the Midwest, forming what was known as Gammorin's Army, and many of them eventually ended up joining the Midwestern Brotherhood of Steel.

In 2236, the Enclave, the remnant of the pre-Great War American federal government, discovered the remnants of the Mariposa Base. Soon, Enclave assault squads combed the desert for slaves they could use to excavate the military base and get to the FEV vats. In 2237, having obtained the necessary data and samples to recreate the FEV, the Enclave abandoned the site after more mutations occurred among Enclave personnel exposed to the FEV remnants in the facility, causing a second generation of Mariposa super mutants to arise. The Enclave left a single squad behind to wipe out the super mutants, but the mutants, using armaments they had cached in the base during the excavation, reduced the squad to ashes after suffering heavy casualties. The remaining 1st and 2nd generation super mutant slaves were sealed inside the base by Enclave sappers, who collapsed the entrance to the ruined facility. Inside, the mutants formed a new community.

East Coast mutants
By 2277, the super mutants had also appeared on the East Coast of the United States. These super mutants were created in the Evolutionary Experimentation Program, the experiment which had been assigned by Vault-Tec and the pre-Great War American government to Vault 87 as part of the clandestine Vault experimentation program. The heavily modified strain of FEV which created these mutants resulted in a new strain of super mutants which, in addition to becoming senile, grow much larger and stronger as they age. They are different from their Core Region counterparts as they are green-yellow in skin color and less intelligent. Every super mutant's facial expression is permanently set in a sneer. However, unlike their counterparts, they are even less like pure strain humans, and after the transformation no clues on how they looked in their former lives can be found. They take human prisoners across the Capital Wasteland to transform them into more super mutants by injecting them with the FEV still found in Vault 87. Just as on the West Coast, the by-product of the Vault 87-based creations are the hideous chimaeric mutants called Centaurs, who act as watch/attack dogs for their super mutant masters.

History
During exploration of Vault 87, information from a computer terminal reveals more about the process of mutation that super mutants go through, at least when it comes to the specific modified strain of FEV found in the super mutants of the Capital Wasteland. As a human mutates, its muscular and skeletal systems develop rapidly, while their mental faculties diminish. Most secondary sexual characteristics are eliminated, transforming the subject into an almost asexual state.

Despite their general lack of intelligence (even when compared to the least intelligent of the West Coast super mutants), they are somehow able to organize themselves into a coordinated army (as evidenced by their numerous raids and the attempt to reinforce their positions at the Capitol which led to the attack on Galaxy News Radio), procure large amounts of advanced weapons, ammunition, and equipment, and even maintain the biomedical infrastructure necessary to infect humans with the FEV and increase the numbers of super mutants in the region.

In the urban ruins of Washington, the super mutants are looking for more sources of F.E.V and more humans to expand their own numbers as they seek to take over the entire Capital Wasteland.

Appearances in games
Super mutants appear in all Fallout games.