An accidental dose of red kryptonite turns Superman (Danny Dark) into a child, leaving him prey for Mr. Mxyzptlk (Frank Welker) in this short feature from Super Friends: The Legendary Super Powers Show. Blame this one on writer Kimmer McDonald for giving the Wonder Twins amnesia regarding the various colored variations of kryptonite, six years after they'd first been acquainted with Red K.
I wouldn't have minded at all if Jayna got to quote Oliver Hardy's oft-used catchphrase. She could've told brother Zan, "Here's another fine mess you've gotten us into.". Or it could've gone the other way around.