Batman (1940) #182
80-Page Giant. Written and drawn by Bob Kane. Six of the most bizarre adventures of the Batman and Robin, the Boy Wonder. Over the years, the Dark Knight Detective has had many weird encounters with criminals warped by science and with the strange and often dangerous effects of physics gone wild. Here are a half-dozen of his strangest encounters. First off, the Caped Crusader faces off against a lab assistant turned criminal who has gotten the ability to change into any substance he can imagine, making him "The Villain of 100 Elements."
Then, Batman and Robin trade roles as they become "Batman, Junior and Robin, Senior!" Next, Robin must cover up the apparent death of Batman in order to capture a master criminal by using the "Batman Robot." The Dynamic Duo are shrunk to the size of field mice as part of "The Experiment of Professor Zero." And, Batman trades in his dark costume for uniforms of many colors in "The Rainbow Batman." Finally, the Batman trades minds with his greatest foe and becomes "The Joker Batman!"