context: The Batman/Bruce Wayne (Lewis Wilson), and his ward, Robin/Dick Grayson (Douglas Croft), secret government agents following the Japanese attack on Pearl Harbor, become aware of a Japanese sabotage ring operating in Gotham City. Bruce's girl friend Linda Page (Shirley Patterson) asks for his help in finding her uncle, Martin Warren (Gus Glassmire), who was abducted by the ring after he was released from prison.
  Dr. Tito Daka (J. Carrol Naish), the Japanese leader of the ring, plans to steal the city's radium supply to power his invention, a hand-held raygun that can dissolve anything hit by its powerful beam. He forces from Warren the location of the vault where the radium is stored. Daka sends his American henchmen, along with a zombie that he controls by microphone via an electronic brain implant, to steal the precious metal. Batman discovers the plot and eventually routs the gang after a terrific battle.
  In his secret underground bat cave, the Batman interrogates one of Daka's henchmen, who reveals the radium was to have been taken to The House of the Open Door, located in the mostly deserted "Little Tokyo" section of Gotham City. Batman and Robin infiltrate the gang's lair (also Dr. Daka's laboratory), hidden inside a still-open business, a Fun House ride. There, they find Linda bound, gagged, and unconscious. After she is rescued by the Dynamic Duo, Daka transforms her uncle Warren into a zombie, and plots the derailment of a heavily laden supply train. Once again, Dr. Daka's sabotage efforts are stopped by the Batman and Robin.
  Traps and counter-traps follow with breath-taking rapidity. The Dynamic Duo continue to thwart the plans of the Japanese agent and his henchmen. When Dr. Daka attempts to steal America's Victory Plans, the Batman prevails, overseeing Daka's final destruction and the capture of his traitorous gang members.
question: Who is the final villain?
answer: Dr. Daka