5. Matt Damon - Aquaman/Martian Manhunter
After Ben Affleck was confirmed as Bruce Wayne/Batman in Man of Steel part deux, distraught fanboys joked his long-time buddy Matt Damon should come on as Robin. While that made little sense and was created out of antipathy to Affleck's casting, later rumors asserted Damon was being considered for a part in the superhero epic, just not as Robin. Who, then? Allegedly, Damon is being looked at for the roles of Aquaman and Martian Manhunter, no doubt stacking the deck for a Justice League team up. While this is likely the most ludicrous of casting rumors on this list, they should all be consumed with a couple grains of salt.