Gigamoth is a divine moth Kaiju and is one of the very first Kaiju to appear on Terra. She is currently one of the original Eight Guardians of Terra and is the Kaiju of Earth. Gigamoth is also he ancestor/mother of the Guardian of Mortals Mothra and Guardian of Terra Battra. 65 Million years ago, she and the other guardians defeated King Ghidorah and DesGhidorah. 77,000 years ago, Gigamoth and the others were forced to defeat the Eighth Guardian after he went rogue, resulting in the remaining guardians to sacrifice their souls to save the human race from extinction but not before laying her egg containing both Mothra and Battra.
Being a divine moth, Gigamoth's appearance is similar to Mothra but has some major differences. In place of fur like Mothra, Gigamoth has a silver armor exoskeleton around her body, with her underside being made up of black flesh. She has six legs which are also armored. As a moth, Gigamoth has massive wings though their edges are covered by the armor, her wings has a rainbow colored design. Her eyes glow a bright green and her antennae are covered in the silver exoskeleton, she also posses as set of mandibles. Her abdomen has a pointed end, and along it are glowing green areas.
Gigamoth was created millions of years ago along with the other original Eight Guardians of Terra. Years after Terra was created, the Tree of Life came into existence and created Gigamoth and the other guardian Kaiju. Like her siblings, she was given an element to keep balance and order on Terra, in Gigamoth's case she was given the element of earth. During the Late Cretaceous Period, King Ghidorah and DesGhidorah invaded Terra in a joint attack, which caused the extinction of the dinosaurs. Gigamoth was able to defeated DesGhidorah by sealing him underneath Infant Island while her fellow guardians where able to send King Ghidorah in retreat, forcing him off Terra
About 77,000 years ago when the first civilizations had appears around the world, one of the eight guardians when rogue and caused great destruction, resulting in another mass extinction, resulting in 10% of the human race remaining. Gigamoth and the other guardians fought against their former comrade and sealed in away and sending him into outer space to prevent anymore destruction. In order to save the rest of the human race, Gigamoth and the remaining guardians sacrificed their souls to the Tree of Life, which managed to restore the human population. Before she could sacrifice her soul to the Tree of Life, Giagmoth laid and egg which contained her successors in protecting Terra while she was gone: Mothra and Battra. Gigamoth and her fellow guardians where placed in a state of limbo as they watched over the humans on Terra as well as other universe.
Post-Trilopod War Arc
Ten months after the Trilopod War, the last of the templates dedicated to the Eight Guardians of Terra still stands on Monster Islands. Before Godzilla is about welcome Manda into the Earth Defenders, they discus how the Eight Guardians of Terra defeated King Ghidorah and DesGhidorah.
In 2016, after both the Earth Defenders and the Earth Conquerors had been sucked through a magic circle from Terra to Earth Land, Gigamoth and her fellow guardians are observing Godzilla through a glass orb as the King the of the Monster reawakens in the Fairy Tail guildhall. Tornaq asks about how the kaiju where transported from world to world, Gigamoth states they are still investigating but suspects the source to be dark magic. When Orikalkos states that he wished they wouldn't become involved with Terra again, Gigamoth states that it would have been a matter of time before they would focus on Terra once again.
Soon after they consult Orochi, the group encounters the first master of the Fairy Tail guild: Mavis Vermilion, who's position on the situation is and Mavis suggests that Godzilla and the Earth Defenders should stay in Earth Land with Fairy Tail. The group gives Mavis's idea a chance while they attempts to locate SpaceGodzilla and his Earth Conquerors. The Guardian Kaiju continue to watch over the Earth Defenders as they join Fairy Tail.
Tenrou Island Arc
In Earth Land whilst on Tenrou Island during the S-Class Wizard Trial, the Shobijin tell the Mirajane Strauss and Lisanna Strauss about Gigamoth and the other Guardian Kaiju, they tell the take-over mages about the history of the Eight Guardians of Terra.
Gigamoth and the her fellow guardians observe the war that the Earth Defenders and Fairy Tail are facing with the Earth Conquerors and Grimoire Heart. Gigamoth states that the war is about to reach the final battle. The Guardian believe that the Earth Defenders and Fairy Tail could perish but Orochi has a plan. Upon realising what they plan is, they are shock as they think they are unable to perform the plan in their current state. As Orochi states they are running out of time, Gigamoth agrees with her sibling and states that while she agrees its a long shot, they have not other options. Soon the rest of the guardians are in agreement as they focus upon the cocoon of Gigamoth's grand daughter: Mothra Lea.
Immense Strength: In the past, Gigamoth possessed great strength. Along with his fellow guardians, he was strong enough to defeat DesGhidorah as well being able to combat the corrupted guardian kaiju.
Immense Magic Power: Being a divine moth, Gigamoth posses great magic power, she was able use this power on DesGhidorah as she was able to place a seal on him and send under Infant Island which is trapped to this very day.