Super Mutant

Super mutants are mutated humans, product of a Forced Evolutionary Virus infection. They have (mostly) green skin, are immune to disease and radiation, and are blessed with exceptional strength and endurance. They also possess the exceptionally long life of the mutated as well as total sterility.

Master's Army
Super mutants were created by Richard Grey, who led the expedition to Mariposa Military Base in 2102. When the expedition was attacked by robots, he was himself dipped in a FEV vat, and managed to crawl out. FEV was initially meant to be injected into humans, but Grey soon found out that direct physical contact worked as well. He began to mutate in horrible ways, turning into a blob of flesh-like material. He developed psychic powers, which were enhanced by consuming living minds to expand his own brainpower. Slowly, as wanderers made it into the base themselves, he started doing his own experiments with FEV. Grey--who now called himself the Master--lamented the needless destruction of the Great War. In his warped state, he decided that he would have to force humanity to evolve. If everyone could be as perfect as his super mutants, there would be no more conflict. Those who could not evolve would die. Around 2155, the Master began seeking out uncontaminated humans with which to create mutants and build his super mutant army.

However, creating super mutants was a very hit or miss process. The great majority of super mutants produced by the Master and later his Lieutenant in Mariposa's Vats were big, dumb brutes. Physically, there were vastly superior to humans, but they had the intelligence of children. What exactly causes some mutants to be brilliant and others to be stupid is unknown. The Master was certain it was related to radiation damage: humans who hadn't been exposed too much radiation yielded smarter mutants (see his personal diary for his thoughts on this). His Lieutenant, however, had a different theory. When the bombs hit the research facility and turned it into the Glow, they cracked open a few tanks filled with FEV. The bombs' radiation then mutated this FEV into an airborne strain. But this new airborne FEV didn't have any real mutagenic effects on people. All it did was inoculate human subjects against the real FEV, acting as a sort of vaccine. The ideal dipping subject was someone who hadn't been exposed to the airborne FEV. Both of these conditions--no radiation exposure and no mutant FEV inoculation--were present in one population: Vault dwellers. Each Vault contained around 1,000 viable subjects to be dipped and turned into super mutants. Which factor exactly determines what you'll get from a dipping--radiation or inoculation--is still uncertain, though as a rule of thumb, the cleaner the subject, the better.

Fall of the Master
In 2262, a man known as the Vault Dweller destroyed the mutant army by causing an explosion in the FEV vats at Mariposa, which collapsed the entire base, and later killing the Master. Without the leadership of their creator and his lieutenant, the mutants divided into at least three factions. One, led by a mutant called Gammorin, of them decided to leave California and find a place for themselves somewhere in the East. Another, led by Attis, wanted to continue the Master's work, rebuild the army, and dominate Southern California once again.

Some super mutants, however, especially those who retained more of their intelligence than their less pure brethren, wanted to make peace with humans, put old differences aside and work together to rebuild the world after the War. In 2185, super mutant Marcus and Brotherhood of Steel Paladin Jacob crossed paths in the desert and punched and shooted each other for a few days. Eventually, they gave up, unable to get an advantage over the other. The two started traveling together, arguing over Master and BOS doctrine. Eventually the two, along with the trail of ghouls, humans, and super mutants, founded the community of Broken Hills.

Second Generation
In 2236, the Enclave discovered the remnants of the Mariposa Base. Soon, assault squads combed the desert for slaves they could use to mine the military base and get to the Vats. One of the squads included soldier Frank Horrigan. Enclave construction crews, as well as human and super mutant slaves began excavations. In September they uncovered FEV, and mutations began to occur in the human workers. Frank Horrigan comes into contact with the virus and is sent to the Enclave labs for study.

In 2237, having obtained the FEV data, the Enclave abandoned the site after more mutations occured, causing 2nd Generation super mutants to arise - the Enclave left a single squad behind to wipe out the super mutants, but the mutants, using armaments they have cached in the base during excavation, reduced the squad to ashes after suffering heavy casualties. The remaining 1st and 2nd Generation super mutant slaves decided to remain in the Base, and the group forms a new community under the leadership of Melchior, whose magician talents had allowed them to hide the weapons.

Gammorin's Forces
Some time after their departure, the faction led East by Gammorin was pursued by Brotherhood of Steel airships. While most of them ended up in the vincinity of Chicago, far from Gammorin's forces, one of the zeppelins crashed north of the mutant encampment. The leader, Paladin Latham, challenged Gammorin to a single unarmed combat and, to surprise of everyone, killed the mighty mutant. As he defeated the previous chieftain, the super mutants expected him to become the new leader of their army. Latham suffered a head injury during the combat, and throughout the years, he grew more and more insane, even though he managed to organize the mutant forces into an army nearly as powerful as they had been during the Master's reign.

When Latham's forces encountered Calculator's robots from Vault 0, he swore an oath to destroy the cybernetic menace. By that time, he assumed the name "Gammorin", after the mutant chief he had killed. Ironically, his forces were defeated by a splinter faction of the Brotherhood of Steel from the Chicago area. After the defeat, many mutants were, however, allowed to join this Brotherhood to fight against the robots.

Appearances in games
Super mutants appear in all Fallout games.