Superman - The Mechanical Monsters

According to the research of 'renegade historian' Douglas Dietrich (website), the 'mad scientist' in these early Superman cartoons is based on Nikola Tesla who by this time (1941) had fallen from grace with the US authorities by refusing to share his work exclusively with the US (he wanted to share his Free Energy work with all mankind, but the US elite was more interested in his potentially devastating weapon technology, hence his reluctance to deal with them). The US propaganda machine consequently started to attack him and demonize him in films such as this.

A more overt hitpiece on the man and his work is the 1944 film 'Return Of The Vampire' starring an ageing Bela Lugosi as 'Armand Tesla'. By the time this particular film was released, Tesla was dead (a possible suicide in early 1943) and a large amount of his work had been smuggled out of the US back to more appreciative and somewhat less aggressively-minded scientists in his native Serbia.