Max Fleischer’s early cartoon, “The Robot”, featured his franchise character Bimbo, but if you look closely you’ll see that a nascent Betty Boop is Bimbo’s co-star. I reckon that’s Felix the Cat moonlighting as the referee, too.
The robot that features in “The Robot” (1932) was rather ahead of its time. Not only is it a robot, but it’s also a transformer and has definite mecha characteristics.
Robot War Espresso 