Mothra theme song - YouTube
Godzilla vs Mothra ( 1992 ) " Birth Of Adult Mothra " - Akira Ifukube - YouTube
Two recorded prayers to the entity known as "Monsura," divine protector of the Earth (though not necessarily of humanity). One of the few creatures capable of defeating Godzilla, Monsura (Mothra in English) has battled threats from Outside on numerous occasions to preserve the planet and its ecology. It is worshiped by the primitive inhabitants of an isolated Pacific island (the exact name and location keeps changing) and is served by a pair of identical dimunitive priestesses who are apparently some sort of supernatural beings themselves. They control access to the deity.
Monsura engages in a continual cycle of growth, death, and rebirth. Its massive winged form never perishes without leaving one (sometimes two) giant eggs ready to hatch, the larvae ready to avenge their mother and take her place the instant they hatch. In "Godzilla vs. Mothra vs. Battra" it was possible for humans, acting in a just cause, to summon Monsura by singing her prayers and/or by recreating her symbol (a cross combined with a circle) in a place open to the sky. Despite their offenses against Nature, people are part of the Earth's ecosystem, after all.
So, is there a place for a "friendly" monster-god in Call of Cthulhu? Mothra certainly would oppose alien beings seeking to corrupt the world, and has the power to do so. On the other hand, we're talking about an insect the size of a battleship, so she'd cause SAN loss just like any Mythos entity. Friendly or not, she's big, bulky and can cause a lot of collateral damage merely traveling from Point A to Point B in a crowded urban setting. Both her priestesses and her human worshipers have had bad experiences with foreigners (the Japanese, American military personnel) and are apt to be hostile or suspicious if contact is attempted.
What do you think? And how would you stat her up?