The Mechanical Monsters is a 1941 Superman cartoon.
Summary[]
A mad scientist is using a collection of giant robots to steal money and precious items around Metropolis. Clark Kent and Lois Lane are assigned to cover the story. The Mad Inventor sends his robots to a jewelry store to steal a large collection of gems. During the chaos, Lois tries to stop the robots, but is trapped inside the hull of one of the gigantic mechanical monsters. Quickly, Clark Kent heads into a phone booth and changes to Superman. He follows the fleet of giant robotic crooks, but is stopped when he becomes tangled in a power line. Lois is found by The Scientist and is tied to a chair, and is about to be placed under a kettle of molten metal. Superman escapes the power lines and flies to the mountain hideout of the renegade inventor. He not only saves Lois Lane, but destroys the robots and captures their crazed creator.