And there is another character who was never seen on 'Batman', as well as a few other TV series*, but whose work was evident in almost every episode. I'm talking about the inventor who created all of the deadly traps and other dangerous props used by the villains in their attempts to subdue and kill the Dynamic Duo.
One such prop can be found in the 'Batman' episode "Death In Slow Motion" - a giant book that had been made for the Bookworm.
Astute readers and avid fans of 'Batman' must think they found an error in that statement above. After all, it was a prop used by the Riddler which contained two riddles for Batman & Robin.
This is true; however, I said it was made for Bookworm. But at the time, the Bookworm couldn't take possession of it from the avaricious artisan who built it. He may have been in prison, perhaps short on the funds needed to pay for it. Whatever the case may have been, the Riddler bought it for his own use in his silent film caper.