The brainchild of inventor Goro Ibuki, Jet Jaguar is a multi-functional robot. Humanoid in appearance and stature, it contains a self-programed function that allows it to grow to gigantic size to defend Earth from the threat of evil giant monsters. Initially enslaved by the people of Seatopia and forced to guide their monster gaurdian, Megalon, Jet Jaguar eventually broke free of their domination and summoned Godzilla for help. He put up a valiant fight against Megalon but was ultimately overwhelmed when Gigan arrived and sided against him. he was saved from toal defeat by Godzilla. the two combined their power in an all-out battle that proved Jet Jaguar to be a loyal, resourceful, and valuable ally for the Monster King.