Worst Godzilla Concept?

Regardless of what you thought of the movie, game, or story; what do you think is the dumbest concept ever concieved in the Godzilla series?

Something like "a monster made out of pollution" or "a giant robot version of Godzilla" sounds really silly when you think about them. Now, I know the original concept of "A giant radioactive dinosaur" sounds dumb to begin with, but which one do you think is the most absurd?

For me, it would have to be the concept of Megalon. As if Gigan wasn't a stupid sounding idea already, they had to think up: "Hey, how about a giant beatle that lives underground who throws bombs out of his mouth and has drills for hands?" Again, your opinion of the material doesn't matter, just what you think of the original concept.