Inventor

The Inventor was an evil genius. His real name unknown, he was the creator of the gigantic robots which would become known to the general populace of Metropolis as the Mechanical Monsters. He used the robots to rob banks and museums of their valuables, controlling them from his mountaintop lair.

When one of the robots returned with a captive Lois Lane instead of the debut exhibit of the House of Jewels, the Inventor threatened to lower her into a pit of molten metal if she did not divulge the location of the jewels (which had fallen out of the robot's storage compartment in mid-flight when Lois attempted to escape from the compartment herself).

Superman arrived to save Lois and stop the Inventor, who sent his entire army of robots against him, but the Mechanical Monsters were not match for the Man of Steel. He destroyed the robots, saved Lois, and the evil Inventor went to prison.