Dr. Paul Carruthers, played by Bela Lugosi, is a character in the film The Devil Bat.
Dr. Paul Carruthers is offered a $5,000 bonus for his contributions to the company he's made millions of dollars of profit for. Outraged at the pittance offering, he schemes for a way to punish those who work in the company.
He has experimented on bats, making them grow to an astonishing size. He has also trained them to be attracted to a specific after shave that he gives to those he feels have wronged him. One by one the giant bat kills those from the company. It's not until during a climactic fight with Johnny Layton that the plot ends. Layton spills the after shave on Carruthers, thus causing the bat to attack and kill him.