=What's the work?= ''Superman'' was a series of seventeen animated short films released from 1941 to 1943, originally produced by Fleischer Studios and later by Famous studios (earning the series the nickname of "The Fleischer ''Superman''). They told stories of the Man of Steel himself, stopping crime and assuming his secret identity as mild-mannered newspaper reporter Clark Kent.
=The villain:= The man simply known as the Mad Scientist is the one-shot main villain of the first animated short, simply titled ''Superman''.
=Who is the Mad Scientist? What has he done?= The short begins with the Mad Scientist sending a threatening letter to The Daily Planet, telling them that he plans to unleash his "Electrothinasia Ray" that night at midnight, taking revenge on Metropolis for "laughing at me and failing to heed my warnings".
As he promised, at midnight, the Mad Scientist powers up his ray and aims it at the city. However, he is alerted by his pet raven that Lois Lane is arriving to investigate. Upon her arrival, he violently attacks and kidnaps her, tying her to a chair and gagging her, telling her "You want a story? I'll give you the greatest story of destruction the world has ever known." He then forces her to watch him carry out his plan as he fires the ray at a busy bridge, destroying it. A radio broadcast confirms that the "deadly impact of his mysterious ray smashed the famous tower bride, hurdling cars and pedestrians into the river below". Clark Kent hears the broadcast and changes into Superman, flying off to stop the Mad Scientist from taking any more lives.
However, as Superman is on his way, the Mad scientist aims his ray at the bottom floors of The Daily Planet building, destroying them and killing those inside (yes, they show the flaming debris falling on the people inside) and causing the building to begin to collapse. Superman turns around and stops the building from falling, then straightening it upright. Superman jumps into the ray's beam, blocking it from hitting the building. When the Mad Scientist sees Superman in the ray, he turns up the power, blasting Superman to the ground. Superman is able to recover and push the beam back, despite the Mad Scientist continually upping the power to try and kill him. Superman eventually makes it to the canon and ties the barrel in a knot, causing the ray to backfire and begin to explode. The Mad Scientist attempts to flee and leave Lois and his pet for dead, but Superman frees Lois and grabs the Mad Scientist as the lair collapses. Superman rushes to the prison and throws the Mad Scientist in a cell, locking him away to await justice.
=Mitigating factors?= The Scientist claims that people "laughed at him" and that is why he is seeking revenge, but they never reveal what they were supposedly laughing at him for. I think it's implied that it was The Daily Planet dismissing him as a lunatic (as that's why he sends his threat there and targets their building), but it isn't made clear.
He also has a pet raven, though he barely interacts with it and leaves to die later, so it's clear that he didn't really care about it.
This cartoon also came out in 1941, so the violence is pretty tame by today's standards, though it does get pretty dark for the time period by actually showing people dying and having a radio broadcast confirm casualties in his attacks.
=Heinous standard?= The series is one of superhero adventures, but in all the other shorts, the threat is a natural disaster, amoral animal/monster, or disposable generic thugs. The closest in terms of destruction was ironically another scientist in the short The Magnetic Telescope, but his destruction was more an accident as his magnetic telescope accidentally pulls a metal comet to Metropolis while he is experimenting with it.
=Verdict?= It's weird considering the time period it came out for them to actually give a body count to a character (I dunno, it's just so surreal to me) but given all he did, I have to lean towards "yes".