No Export for You: The film was not theatrically released in Spain until 1979, 13 years after its premiere.
The Other Darrin: Lee Meriwether as Catwoman. Julie Newmar had no idea the film was even being made and had signed on to another project. By the time she was informed, she could not get out of the other commitment in time to do this movie.
Recycled Set: The Penguin's submarine interiors are the Seaview sets from Voyage to the Bottom of the Sea (1964) redressed.
Stillborn Franchise: A follow up film was at one point considered. The film would have been released between seasons two and three, and would have been used to introduce Barbara Gordon/Bat Girl, and make use of a Batplane. Due to waning interest in the series during season two, which resulted in budget cuts, plans for a second film were scratched.
Throw It In: Penguin's "every one of 'em has a mother" was an ad-libbed line.