An alpha predator species belonging to an ancient and now extinct organism. Godzilla was bombarded with high density radiation during Earth's Paleozoic Era, enhancing his abilities. The beast was able to escape the mass extinctions on the surface by traveling into the deep sea during the Permian period.
The creature lay dormant for eons at the bottom of the ocean, but would occasionally venture to the surface. During these periods, the gigantic kaiju would often be sighted. This led to paintings and other documented evidence dating as far back as 30,000 B.C..
In 1954, several sightings of Godzilla occurred. They begun after the creature was awoken by a Soviet military submarine accident. Both the Soviet Union and the United States unsuccessfully attempted to eradicate the kaiju with nuclear weapons. These strikes were covered up as tests to the public. In March of 1954, Godzilla made his presence known to MONARCH, an organization tasked with learning about giant mutations. The kaiju rose to do battle with Shinomura, an ancient species that Godzilla had fought before. The Shinomura species is capable of dividing and joining as an organism, so as Godzilla destroys one with his atomic ray another divides and survives. The King of the Monsters hunts the last of the Shinomura, tracking them down to the Bikini Atoll. With the creatures in range, the United States military decides to launch a nuclear bomb, hoping it will kill both. The weapon is detonated. Both monsters vanish in the blast, prompting the military to assume the strike was a success. MONARCH is not convinced, believing that Godzilla survived.
It takes 50 years before MONARCH's theory is proven correct. In 2014, during an outbreak caused by the MUTO, another ancient species, Godzilla reemerges. Drawn by it's echolocation signal, Godzilla arrives at Honolulu, Hawaii, the current location of the MUTO. The King of the Monsters prepares to battle his ancient rival. Engaging the winged male of the species, who earlier was feasting on the remains of a Russian submarine, Godzilla drives the MUTO away. The insect-like creature flies off, as Godzilla swims after in pursuit.
MONARCH is puzzled why the MUTO would be seemingly calling Godzilla. The organization realizes, though, that the signal was not meant for Godzilla: it was meant for the female of the species.
Appearing in Las Vegas, Nevada, the female travels further toward the coast, in the direction of San Francisco. Seeing this as the likely battleground, the United States deploys the NAVY to the area. Filling the San Francisco Bay with warships, the military also docks a nuclear missile to act as bait. Drawn to the MUTO, Godzilla appears from the Gulf of the Farallones, narrowly swimming below several battleships. Attempting to drive him away from the city, the NAVY opens fire on the monster. They are unsuccessful, though, in deterring Godzilla. The King of the Monster surfaces near the Golden Gate Bridge before breaking through the structure and advancing toward the city.
Meanwhile, the male MUTO arrives and unleashes an EMP attack, neutralizing the fleet and the air support. The winged creature quickly dispatches the warship carrying the nuke. It then drags the warhead toward San Francisco's downtown. Once there, the creature rendezvouses with the female. The smaller male creates a perimeter while the female rips apart China Town to create a nest. Godzilla arrives inland and advances, engaging the male MUTO in the process.
Eventually, the female joins in the conflict, tag-teaming Godzilla. As a pair, the MUTO gain the upper hand against the larger kaiju. Their advantage is short lived, however. When the military destroys the MUTO nest after extracting the nuke from the site, the larger MUTO becomes distracted. Before the female can get her revenge for the nest's destruction, though, Godzilla charges his atomic ray, unleashing it against the larger MUTO. The blast pushes back and knocks down the female, but she is saved through the intervention of the male. Godzilla delivers a killing blow, though, to the winged male by slamming it into a building with his tail. The power and speed of the impact cause the building derbies to literally lodge itself through the MUTO's body, impaling and killing it. Unfortunately, the strike destroys the skyscraper, which buries Godzilla as it collapses.
Meanwhile, at the docks, the military is trying fruitlessly to transport the nuclear weapon out of the city. Hoping to get it a safe distance before it detonates. The female, looking for revenge for the nest, kills almost everyone at the location. She is stopped from securing the nuke, however, as she is dragged by the neck from behind. Godzilla, surprising the MUTO, forces the female's mouth open and unleashes a pointblank atomic blast. The intense heat builds in the neck of the large MUTO until it ruptures, severing the giant's head. The King of the Monsters tosses the beast's head into the San Francisco bay as it roars triumphantly. Godzilla then staggers before collapsing in the Embarcadero area of the city.
The next morning, rescue crews are working around the city, surrounding the believed corpse of Godzilla. The kaiju opens its eye, though, to briefly witness the humans around him. The nuclear titan then gets up, footage of which is broadcast as news teams hail the creature as a "savior" and the "King of the Monsters". Godzilla approaches the water near the Bay Bridge before once more diving beneath the surface.