This is the first Part 1 episode which ends with Dozier saying "Same Bat-Time, Same Bat-Channel," though the onscreen card still reads simply "Same Time, Same Channel," indicating it might have been a last-minute ad-lib.
The opera mask worn by the Joker in this episode was also the design for the mask he wears during the opening scene of The Dark Knight (2008).
This episode and its followup were based on the comic book story "The Joker's Utility Belt", originally published in Batman #73 (October-November 1952). The writers of the show probably became aware of the story when it was reprinted in Batman #176 (December 1965).
About 12-13 minutes into this episode, Batman and Robin are asking the man at the front desk of the Gotham City Museum to close the museum. Behind Robin is a human figure riding on the back of a dolphin. This 'dolphin' figure was one of two matching figures that are seen in The Poseidon Adventure (1972) on each side of the forward end of the Poseidon's ballroom (where the Christmas tree is located). They sit on a lit up shelf in a recessed area of each wall.
Joker has four henchmen in this episode. All are named for famous comics. As the series progressed, most villains would have three named henchmen.