From the 'Are you kidding' department.. A coat purchased at a used clothing store as part of the Professor Marvel's costume in the Wizard of Oz movie turned out to be once owned by.. L. Frank Baum himself! Yes! A coat owned by the author of the Wizard of Oz ended up on screen worn by Frank Morgan who portrayed Prof. Marvel and the Great and Powerful Oz himself. Is this coincidence too good to be true? Nope! It has been confirmed by several members of the film crew. It turns out that Morgan discovered Baum's name sewn into one of the coat pockets. The tailor and Baum's widow were contacted, and both identified the coat as having once belonged to the late author.