Godzilla

Physical
Godzilla is large, with a reptillian look to his bipedal form. He has gills on his neck, and web-like fringes around his neck. His snout is a squarish shape, and flat on the front, and the top of his head is diamond-shaped, like a snake's. He shares similar features with Millennium Godzilla, maintaining his reptillian nature. His dorsal plates are spiked and rigid, much like Millennium Godzilla as well. In King of the Monsters, his dorsal plates have changed shape to be much more like the traditional maple-leaf shape, much like Heisei Godzilla.

Roar
Godzilla's roar in the Monsterverse is a longer, shrieking hiss, with a deep breathing in at the end. The team that created the roar wanted it to have a more realistic feel, and managed to retain the spelling of "Skreeeongk" like the previous roars. According to Gojipedia, "The final version that was created was the 50th the team produced. The pair tested the roar on a back lot at Warner Bros., using a 100,000 watt tour speaker array for The Rolling Stones. The roar was powerful enough to rattle pipes and rooftops, and was estimated that it could be heard up to three miles away. For this experiment, the crew actually sent out fliers to surrounding communities warning the neighbors about the potential sound disruption; despite these preemptive measures, however, Burbank P.D. started getting calls and people were tweeting 'Godzilla's at my apartment door!'"

In King of the Monsters, Godzilla uses revamped Showa roars combined with the roars from the previous movie as well. On four occasions does he use them, At the very beginning in the opening credits, the first roar is heard, which is a combination of a longer legendary and showa roar combined. Then again, during his fight with Ghidorah in antarctica, he uses a 1954 roar (also combined with a legendary roar) and again in the same fight, he uses a revamped Showa roar by itself when he falls into the pit Ghidorah came out of. The last time a Showa roar is used is when he arrives in Boston, where an excellently revamped classic Showa roar is heard. In addition to all this, he uses some recycled legendary roars that have been altered in one way or another, sometimes lengthened or shortened. There are also some new groans and moans, some of which sound elephant like, used in both times where he charges at Ghidorah, and multiple times when his energy is being drained by Ghidorah.

Personality
Godzilla's personality is rather complex. He sees himself as the true king of the monsters, and will do anything to defend his title. He seems to show violence towards anyone and anything that threatens his alpha status. As for humans, he sees them as smaller insects that he needs to defend in order to ensure the Earth's survival, but still sees them as small, insignificant creatures. However, his respect for them grows as he begins to understand them better, as seen when he falls down in San Francisco and makes eye contact with Ford Brody.

Godzilla, King of the Monsters (Comic)
In an unspecified year during the Earth's precambrian era, Godzilla roams the earth as a younger version of himself. He is suddenly attacked by a much larger creature, whose name is unknown. He is easily overwhelmed, when suddenly, Anguirus attacks the larger creature, throwing him off of Godzilla. The two scare off the larger creature, and an unshakable bond is formed between the two of them. They see Ghidorah's egg enter the Earth's atmosphere, and go to investigate, but they are stopped by Megaguirus. After fighting off Megaguirus, the two go to sleep, after which the story ends.

Ghidorah, the Three-Headed Monster (Comic)
In 1841, King Ghidorah is attacking a group of Whale Hunters when Godzilla intervenes, starting a fight with Ghidorah. At this point in time, Godzilla is a young adult, but maintains his adult-like appearance seen in 2014. After Anguirus joins the battle, Godzilla and his friend push Ghidorah off a cliff between two icebergs, and collapse the iceberg on top of him, freezing him in ice for the next hundred years.

Godzilla: King of the Monsters (Novel)
Shortly after his disappearance in 1954, Godzilla roams the deeper parts of the ocean, trying to remain hidden from the outside world. However, he can't seem to rest, for something seems off. He finds traces of wrecked ships and dead sea life. He follows the trail, which eventually leads him to the nest of the giant sea serpent, Manda. The two clash for two whole chapters before Godzilla drives him off, and can finally go to rest.

Godzilla 2014 (Movie)
In 1954, Godzilla re-emerges, and is studied and promptly bombed by Monarch with the newly-created Atomic Bomb. Years later, he resurfaces again after hearing HOKMUTO's mating call. He heads to Hawaii, where he and the MUTO clash for the first time, then the two retreat. Godzilla follows the MUTO to San Francisco, and, after a brief scuffle with the military at the Golden Gate Bridge, enters the city to once more clash with the MUTO. Eventually, Godzilla makes his way to the MUTO's nest, and engages in a fight with FEMMUTO.

Hokmuto joins the battle, and the two begin to double-team Godzilla, knocking him out. After the MUTOs are drawn away by an explosion in their nest, Godzilla charges up his atomic breath and fires it upon Femmuto, injuring her. He then is attacked by Hokmuto, and quickly dispatches the winged creature by slamming him into a building with his tail. The building collapses on top of Godzilla, and he meets eye contact with Ford Brody, after which he is consumed by a dust cloud. Later, when Femuto tries to eat Ford, Godzilla stops her and pulls her away, and fires his atomic breath in her mouth, severing her head and killing her. He roars triumphantly, and passes out from exhaustion. In the morning, he awakens, and the people cheer him on as he retreats to the ocean, calling him the "King of the Monsters" and "The Savior of our City". Godzilla finally retreats back into the water, where he disappears for the next few years.

Godzilla: Through the King's Eyes (Novel)
Godzilla has many PTSD nightmares from his fight with the MUTOs, and often struggles to sleep. Eventually, the nightmares create a trail of storms that lead him to antarctica, where he comes face-to-face with his mortal enemy, Ghidorah, for the first time in years. Ghidorah, being frozen yet conscious, remembers Godzilla as the one who sealed him in his arctic tomb, and vows that he will kill Godzilla.

Atomic Breath
Godzilla has the ability to charge up absorbed radiation and release it from his mouth in the form of a blue, fiery beam that can deal massive damage. In Godzilla, King of the Monsters (2019) Godzilla's Atomic Breath is larger, and more powerful than in the previous movie. The director explained this was because the MUTOs EMP was affecting his Atomic Breath's power.

Fire Infusion
While it hasn't been explained yet, We have seen in trailers for the 2019 film, Godzilla: King of the Monsters that Godzilla is infused into his burning form. NECA toys have further confirmed this, however he is not called Burning Godzilla, he's instead referred to as "Fire" Godzilla.

Regeneration
Like many of the Godzillas before him, Monsterverse Godzilla is capable of rapid cell regeneration, allowing him to quickly heal during battles, shown in the 2014 movie when he easily gets back up to continue fighting, even after being relentlessly pummeled by the MUTOs.