Man of Steel and Man of Stone-Age, Superman and Fred Flintstone, finally met their match.
A pair of imps, Gazoo from an alien world and Mr. Mxyzptlk of the 5th dimension, with vast power to perplex the lives of our heroes.
Still, their deep-down good nature kept them from caused permanent damage. It would've been interesting to see what damage Gazoo may've wrought on other Charlton characters like Captain Atom or Blue Beetle. Or the metaphysical explanations the Question would give to debunk such a creature's worth. And of course Mr. Mxy was way to anal in focusing only on the Big Blue Boyscout, when there were so many other playmates running around DC Comics.