Mechagodzilla is a mecha that first appeared in the 1974 film Godzilla vs. Mechagodzilla as an extraterrestrial villain opposing Godzilla. In subsequent iterations, it is depicted as a man-made weapon designed to defend Japan from Godzilla. In 2021's Godzilla Vs. Kong a new version a MechaGodzilla is created to exterminate all Titans but is destroyed by Godzilla and King Kong.
Vote which fictional character would naturally fit in-universe with a big-named franchise! No time-travel, no interdimensional crap, no "Pooh's Adventures", they would just exist in-universe.
