Guess who wins?
This is an alternate ending from the 1965 Japanese B classic Frankenstein Conquers the World (Frankenstein vs Baragon), and it is predictably schlocky, amusing and poignant. I always cried when the monster died in these old movies, even if it wasn’t a Harryhausen.
But I still have no idea why Frankenstein grew to enormous size, nor how that Giant Land Octopus got to the top of Mount Fuji.