M.U.T.O.

M.U.T.O. (an acronym for Massive Unidentified Terrestrial Organism) are giant prehistoric parasitic monsters that serve as the main antagonists in the 2014 film Godzilla. Another MUTO is seen in the sequel, Godzilla: King of the Monsters.

Appearance
As a species, the MUTOs exhibit extreme sexual dimorphism as there are several notable differences between males and females. The female MUTO seen in the movie was almost double the size of her male counterpart, and had a more hunched-over stance. She possessed two pairs of massive forelimbs armed with sickle-like claws, and a smaller pair of forelimbs attached to her abdomen. Most notably, the female possessed a pouch-like structure on her lower abdomen, which could hold hundreds of glowing eggs when pregnant. The male MUTO was half the height of his female counterpart, and had a much more nimble, lightweight build. The male had only one pair of clawed forelimbs, as the second pair has evolved to form a pair of long, membranous wings. Similar to the female, the male also had a pair of small, vestigial forelimbs on his abdomen. Both males and females possess long, slender hind limbs that end in broad hoof-like toes, as well as narrow bioluminescent red eyes. MUTOs use the front joint of their claws to walk, bending it and giving it a hook-like appearance.

The second female MUTO seen in Godzilla: King of the Monsters is nearly identical to the one seen in 2014, except with numerous spike-like protrusions across her body, which seemingly indicate older age.

Origins
The MUTOs are a species of massive prehistoric parasites that evolved and thrived during the Permian period. The MUTOs were the natural enemies of Godzilla's species, as both species actively hunted each other. Godzilla's kind hunted the MUTOs and kept their numbers in check, while the MUTOs would hunt and kill members of Godzilla's species and lay their eggs inside the bodies of their prey. Like Godzilla, they feed off of the Earth's natural radiation, but can adapt and feed off of man-made radiation such as warheads and nuclear reactors. At some point in the ancient past, the majority of the MUTOs died off. In 1999, a pair of MUTO spores were accidentally discovered within the fossilized remains of a member of Godzilla's species during a strip-mining operation.

Godzilla
In the Philippines in 1999, a mining operation was alerted to a large pocket of radiation beneath it. The miners believed it was a uranium deposit and continued to dig. The entire mine collapsed into an underground cavern. The scientists Ishiro Serizawa and Vivienne Graham from the organization known as Monarch were called in to investigate what was found in the cavern. Inside, Serizawa and Graham were stunned to find a gigantic skeleton resembling the very creature that they had spent the last several decades searching for: Godzilla. Serizawa noted that although this creature appeared to be of Godzilla's species, it died long ago, long before Godzilla himself was first documented. The scientists also discovered two pods inside of the skeleton, one of which had just hatched. The other pod was deemed dormant and taken to a nuclear waste depository in Nevada. The creature that hatched from the other pod burrowed its way to Japan, to the nuclear power plant in Janjira. The creature breached the plant's reactor and caused a nuclear meltdown, destroying the plant and killing several workers. Monarch quickly quarantined the entire city of Janjira and studied the creature, which had cocooned itself and attached itself to the reactor, feeding off of the nuclear energy. Monarch studied the creature for 15 years, until the creature sucked the reactor dry. Serizawa gave the order to kill the creature before it hatched, but the monster burst from the cocoon and destroyed the facility, killing the armed soldiers firing at it. The creature opened its wings and flew away.

The next day, the United States military codenamed the creature M.U.T.O., an acronym for Massive Unidentified Terrestrial Organism. The military took over operational authority from Monarch and recruited Serizawa and Graham to help them track and destroy the MUTO. The MUTO next attacked a Russian nuclear submarine and brought it ashore in Hawaii, eating the sub's nuclear torpedoes whole. Fighter jets intercepted the MUTO, but it retaliated by releasing a natural EMP from its claw, which disabled the jets. The MUTO flew to the Honolulu airport and caused destruction there before Godzilla himself arrived. Godzilla battled the MUTO, completely devastating Honolulu, before the creature finally retreated with Godzilla in pursuit. Serizawa and Graham eventually concluded that the MUTO was communicating with the dormant pod in Nevada, which actually contained a female member of its species that was waiting for the male to mature. The female MUTO escaped from the waste depository and rampaged through Las Vegas, before heading to San Francisco to meet up with the male. The U.S. military devised a plan to lure both MUTOs and Godzilla offshore with a nuclear warhead, and then detonate it to kill all three. A train carried two nukes towards San Francisco so they could be carried away by boat, but it was attacked by the female MUTO along the way. The female ate one of the warheads, but the other was lost among the train wreckage. The military recovered the other nuke and airlifted it to San Francisco Bay, where the male MUTO arrived and took it away just after it was armed. The male presented the nuke to the female as a nuptial gift in the heart of San Francisco, and she quickly prepared a nest. The male was alerted to the arrival of Godzilla and flew to battle him while his mate laid her eggs. Godzilla battled the male MUTO through San Francisco until he reached the nest. After laying her eggs, the female entered the battle and the two MUTOs double-teamed Godzilla. Before Godzilla was completely overwhelmed, a military team retrieved the nuke from the nest and then blew up the nest with a gasoline explosion. Seeing an explosion in their nest, the two MUTOs abandoned the fight and rushed to investigate, giving Godzilla time to catch his breath. After seeing her young killed, the female roared in rage at Ford Brody, the soldier responsible. Before she could kill Ford, Godzilla blasted the female in the side with his atomic breath. The male attacked Godzilla again, allowing the female to pursue the soldiers. The male tried to fly and ram Godzilla, but Godzilla swatted the male with his tail into a building, impaling and killing it. The female killed all of the soldiers except Ford and prepared to kill him too before he could take the nuke offshore. Just before she could bite down on Ford, Godzilla bit down on the female's neck and pulled her back. Godzilla then pried open her jaws and fired his atomic breath down her throat, severing her head.

Winged M.U.T.O.
The male M.U.T.O. is much smaller than his female counterpart but compensates with his speed and ability to fly. The male M.U.T.O. is approximately 60.96 meters tall, or 200 feet.
 * EMP Attack - The male M.U.T.O. can release an electromagnetic pulse by slamming his claw down, disabling all electronic devices for miles.
 * Flight - The male M.U.T.O. can fly at supersonic speeds to evade enemies and attack them by surprise.
 * Echolocation - The male M.U.T.O. can use echolocation to communicate with and locate the female, as well as locate sources of radiation.
 * Physical Strength - Despite his small stature relative to the female M.U.T.O. and Godzilla, the male M.U.T.O. has surprising strength and can drag the much larger and heavier Godzilla by grabbing him with his claws and dragging him.

Eight-Legged M.U.T.O.
The female M.U.T.O. is considerably larger than the male and has greater physical strength. The female M.U.T.O. is approximately 91.44 meters tall, or 300 feet.
 * EMP Field - The female M.U.T.O. naturally emits an electromagnetic field from her body that disables all electronics in a five-mile radius.
 * Echolocation - The female M.U.T.O. uses echolocation to communicate with and locate the male, as well as locate sources of radiation.
 * Reproduction - The female M.U.T.O. can reproduce sexually by laying hundreds of eggs near a source of radiation.

Trivia

 * Godzilla's enemy in the 2014 reboot was originally intended to be a giant tardigrade monster, but was rewritten into the M.U.T.O.s. The tardigrade monster, which appeared only in a teaser trailer for the film, is often called "Visnhu" by fans.
 * In the original screenplay, the male M.U.T.O. was called "Hokmuto" and the female was known as "Femuto." This was because the male was originally to be discovered in Hokkaido, Japan rather than the fictional city of Janjira.
 * The M.U.T.O.s are the first completely original opponent Godzilla has fought since Destoroyah. The other monsters he has fought since then are all either monsters he has fought before, clones of himself, or are based on another pre-existing monster.
 * The M.U.T.O.s are the third American-made monster Godzilla has fought, the others being King Kong and Zilla.
 * When designing the M.U.T.O.s, Legendary reportedly took inspiration from the creatures in King Kong, the bugs from Starship Troopers, and the Xenomorphs from the Alien franchise. The M.U.T.O.s also share physical similarities with other monsters, such as Clover, Gigan, Gyaos, and Orga.
 * Weta Workshop, who designed and animated the creatures in 2005's King Kong, designed the M.U.T.O.s for Godzilla. Andy Serkis, who portrayed Kong through motion capture in the film, assisted with the motion capture for the M.U.T.O.s.