Within the MonsterVerse, Godzilla and other members of his species like Dagon are prehistoric amphibious reptiles who are the alpha predators of the Earth who keep all Titans in check, make sure those like MUTOs won't overpopulated their species, and make sure invasion monsters won't take control of the planet.

Stats
108.2 m (355 ft) & 90,000 tons (Pre-1100 B.C.)
119.8 m (393 ft) & 99,634 tons (Post-1100 B.C.)

Personality
Despite Dagon looking like a brute, he actually have human-like emotions and sentiment. He take his role as King of the Monsters seriously as he make sure all Titans obey him and if not, then he'll make them no matter what. He is very aggressive if someone trying to take his status of Alpha but have more hatred to MUTOs, Shinomuras, and Meganulons due to them being his species natural enemies. He also more violent towards monsters not part of the natural orders like the Kaijus from the Anteverse, space monsters from outer space, and mutations created directly or indirectly by humans. He have a soft spot for the Devine Moths as they form a symbiotic relationship. He seem very neutral towards ancient humans for worshipping him and build him a place in the water as a home but have deep hatred modern humans due to what their doing to the planet and created weapons design to take down Titans. He developed a psychic bond to Haruo Sakaki due to both of him having similar personality, sorta becoming a father figure to the human. Despite hating Kaijus, he seem kind and gentle to bOy.

Monarch History
The first of thd Titanus Goji Filius to be hatch from Gojira, Dagon was destined to be the King of the Monsters and the apex predator of the Permian ecosystem. His purpose is to make sure that nature and the world is in balance as he fought many Titans who tried to overpopulate their species or take his title as Alpha, which includes some of his sibling. He eventually developed a symbiotic relationship with the Titanus Mosura species as they both have the same goal of protecting the Earth. In the Triassic Period, he led many of the Earth monsters in Titan-Kaiju Wars to fight many of the Precursors' genetically engineered amphibious monsters which cause Pangaea to change and cause radiation level to go low. Dagon was deeply injured and know that the Earth was changed as he and his fellow head to the Hollow Earth and will come out if a dangerous Titan is on the loose. In 1100 B.C., Dagon sense one of his brethrens came to the surface but was infected by a MUTO Prime, he chase the monster then the two fight which the human Phoenicians watch which would called the Battle of Dagon and the Abomination. He suffered lots of pain when the MUTO Prime shattered his dorsal plate but defeated it with a nuclear pulse but quickly got away. Dagon drag his brethren back unknowingly that he holds a future threat that will come. He return in August 6, 1945 as he sense Shinomura awaken and follow them in the water as he was undetected by humans. See search for more as he was spotted by some humans but ignore them, he kept on fight the Shinomura and also a Rhedosaurus from 1946-1950. During that time, the U.S.S. Nautilus almost discovered him but this anger him, he continued to follow the two Titans but a third one, the MUTO Prime return, it attack the Rhedosaurus as she infected it and follow Shinomura. Dagon following the two everywhere more, withstood the Castle Bravo, killed the 2nd Shinomura, and finally battle MUTO Prime. He witness the human Dr. Serizawa using the Oxygen Destroyer to kill MUTO Prime but he quickly escape, he returned to take a long rest. He was finally truly awaken in the 2000 as sense and upcoming danger but also developed a psychic bond and connection with Haruo Sakaki.

Trivia
● My Dagon is my in-universe version of the MonsterVerse Godzilla in the TriStar universe since there is already a Godzilla.
○ Dagon is also a combination of MonsterVerse Godzilla and Dagon who appeared in the beginning of Godzilla 2014 and Godzilla: Aftershock.

● Dagon and his siblings' subspecies named is Titanus Goji Filius, an reference to the MonsterVerse Godzilla and Godzilla Filius from the Anime Trilogy.

● Being born in the Permian period, Dagon is the second oldest of his kind being 298.9 million years old, his mother and progenitor Gojira is 700 million years old.
○ Dagon along with his siblings, Megaguirus & Meganulons, and possibly other Titans are the 4th oldest. Gojira is the 3rd, Destoroyah being 2nd as he's 2.5 billion years, and Gidrah a.k.a. Void Ghidorah who is the oldest monster and live for over 10 billions years.

● Dagon having a psychic bond with Haruo Sakaki is very ironic since in the Anime Trilogy, the original Haruo want to destroy Godzilla.

● Dagon in the present time of seeing humanity being not worthy of living on Earth for not caring for it is a reference to Power Rangers Wild Fury episodes "Monitoring Earth" and "The Soul of Humanity" but unlike Animus/ Kite as it's a test, Dagon actually mean it by attacking humans and location that's harm the natural order.

● Dagon being interested with the Devine Moths is a reference to Godzilla: King of the Monsters (2019), especially the newest Mothra nickname Mosura who is based on that incarnations of Mothra along with priestess being Maina and Miana.
○ This sorta mirror between Titans and their companions, Dagon-Mosura and Haruo-Maina.

● Dagon's relationship with Haruo seem to be sorta similar Sam and Bumblebee from the film, Hiccup and Toothless from HTTYD, and Ash and Charizard from the original Indigo League series.

● Dagon past battle with MUTO Prime and Shinomura is a reference to the event of Godzilla: Awakening and Godzilla: Aftershock.

● Dagon relationship with the hybrid bOy is similar to Baloo and Mowgli from the Jungle Book, the original and remake of the same name.