The Penguin's submarine's interiors are the "Seaview" sets from Voyage to the Bottom of the Sea (1964) redressed.
Adam West agreed to do the film partly on the one condition that he would have more screen time as Bruce Wayne in it.
Adam West points out how fake the shark looks in one of the film's most memorable scenes. He also notes how unhappy the producers were of the sound that was made when Batman was hitting it. West says that he told them that the sound did not matter
because the shark looked so fake anyway.
Shooting of the film began before Lee Meriwether was cast for it. As a result, the Catwoman does not appear with the other three villains in the first scene that takes place aboard the Penguin's submarine in it.
Cesar Romero (the Joker) absolutely refused to shave off his mustache during filming and it was covered with makeup instead. Romero did the same thing in every episode of the TV series that he appeared in as the Joker.