The Batman is already a tremendous success, basically guaranteeing a sequel from Warner Bros, and the use of one of DC Comics' more outrageous villains could avoid unwanted comparisons to Christopher Nolan's Dark Knight trilogy in the future. While many of Batman's enemies have no powers, even the ones that do are fairly grounded characters in scope and don't deviate much from what the famed vigilante is all about. Using one of Batman's more fantastical villains would act as a solid transition befitting the direction these films seem inclined to take. He has no shortage of them, including the likes of Bane, Man-Bat, and, most interestingly, Clayface.
There have been numerous iterations of Clayface over the years. The first, debuting in Detective Comics #40 (1940), was a disgruntled actor by the name of Basil Karlo, driven mad by his being replaced for a role. It wasn't until later iterations, however, that the superhuman angle of Clayface being a shape-shifting mud man was adopted. By far the most iconic iteration, however, came from Batman: The Animated Series, which combined the original Clayface's screen actor background with the powers of later counterparts, creating a tragic character in Matt Hagen, who used a special drug called Renuyu to alter his appearance after an accident left him horribly scarred. Unfortunately, he got this drug from dealings with shady criminals, and an attempt to kill him with the drug resulted in his becoming the mud monster he is now. This iteration was so popular, in fact, that it was later somewhat adapted in the comics, with the Penguin being the source of the drug.
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