"Island of the Dinosoids / Uncle Mxyzptlk" October 13, 1984
Island of the Dinosoids: Ronald Raymond, Apache Chief, Robin, and Wonder Woman get caught up in an island mystery when a science experiment goes awry after Batman and Professor Stein went missing when on their way to the Tokyo Science Expo with Professor Stein's Omnicaster. A scientist named Dr. Dan Corwin had walked into what is referred to as a Geneto Beam and is turned into a Dinosoid, which means half-human/half-dinosaur.
Uncle Mxyzptlk: The Wonder Twins accidentally expose Superman to Red Kryptonite which turns him into a 6-year old kid.