Guest Actor Jimmy Boyd had formerly been married to Yvonne Craig.
Louie the Lilac along with Egghead were never Batman villains lifted from the DC comics and were created specifically for the TV series. Interestingly they have since become known villains in the animated series of Batman. However, Marvel Comics, the other major comic book publisher, did have an Egghead character, with a similar motif as the Bat-villain (adjusted for camp).
To save time and money, the shot of a flat-bed truck full of hippies leaving the park early on is recycled again near the end of the story.
The second of two episodes to feature the full-length version of the Batgirl theme song written by Billy May.
Second actor to appear from Its A Mad, Mad, Mad, World(1963) the other being Ethel Merman in the same season