Super mutant Super mutants are mutated humans , products of infection by the Forced Evolutionary Virus ( FEV ) . 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 virtually biologically immortal ( but not immune to death from injury ) . There are three different known sources of super mutants in the post - War world - Mariposa Military Base in New California ( on the West Coast ) , Vault 87 in the Capital Wasteland ( on the East Coast ) and the FEV labs of the Institute in the Commonwealth ( East Coast ) . The three populations have separate histories and origins , and are yet to interact with each other . While originally the term was only used to refer to the Mariposa stock , the Brotherhood of Steel carried the term with them and applied it to those from Vault 87 upon encountering them . Biology . < section begin = Biology / > Average super mutants stand approximately 10 . 4 feet tall ( although they typically stand with hunched backs that reduce them to about 7 . 8 feet ) and weigh around 800 pounds , possibly even more . Their skin color is predominately grayish green in the case of Mariposa mutants and yellow with tints of red and green in the case of Vault 87 ones , 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 . < section end = Biology / > 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 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 . 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 , but they do lose their secondary sexual characteristics , such as breasts ; Similarly East Coast mutants are said to lose most sexual characteristics While they will not normally 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 . < section begin = WCbackground / > 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 and Institute cousins in the Capital Wasteland and Commonwealth , respectively . Their skin is also darker than that of their east - coast counterparts . < section end = WCbackground / > Background . 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 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 New California once again . A third faction remained in New California 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 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 . By 2281 , some super mutants from both generations had established a community called the State of Utobitha in Black Mountain near New Vegas . The smarter and more organized Master ' s Army remnants are in charge of the dumber second generation mutants . Some other , more peaceful mutants reside in Jacobstown . East Coast mutants . There are two types of super mutants found in the East Coast . 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 sterile , grow much larger and stronger as they age . They are different from their New California 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 chimeric mutants called centaurs , who act as watch / attack dogs for their super mutant masters . By 2287 , a unique large group of super mutants are found in the Commonwealth ; they are experiments of the Institute . This group of mutants also have similarities to the ones from the Capital Wasteland and the West Coast . Unlike the Vault 87 and Mariposa mutants , the ones found in the Commonwealth don ' t have centaurs ; instead they are often accompanied by mutant hound s . Background . 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 FEV and more humans to expand their own numbers as they seek to take over the entire Capital Wasteland . The Commonwealth mutants seem to show more intelligence ( with the exception of behemoths ) than their Capital Wasteland counterparts , as they shout out slightly more intelligent battle cries and taunts . They seem to use better tactics , especially with higher ranking mutants . However , even though they are more intelligent than Vault 87 counterparts , they are still less intelligent and more uncivilized when in comparison to their West Coast cousins . Appearances . Super mutants appear in all " Fallout " games .