The reason Pat Priest was not used in this film was that "Universal" wanted to build up the career of Debbie Watson. Priest was over 30 at the time though Marilyn was obviously college age. In the film, the character was made to be only 19, another reason they cast the younger Watson. This not only devastated Priest, it also angered most of the fans. Additionally, Watson's career never took off.
When Herman (Fred Gwynne) and Grandpa (Al Lewis) are locked in the counterfeiting room and shouting for help, Herman says, "Call Batman," then adds, "Car 54, where are you?" "Car 54, Where Are You? (1961)" was a comedy series that featured both Gwynne and Lewis. Also, "Batman (1966)" was a direct competitor of "The Munsters (1964)" in 1966, and its success and high ratings may have led to the cancellation of the latter series as its viewership significantly declined.
The Drag-u-la car is modified with a real coffin.
The Munsters (1964) move to the big screen came about after the show was canceled having been trounced by Batman (1966). Cast and crew were informed of the series cancellation just before filming on the feature film began, having had a week hiatus after the second season of The Munsters had wrapped. The hope was the film would introduce the series to the world in advance of negotiating future syndication rights.
Released in the United States in mid-summer 1966, this movie was frequently double-billed with the similarly-themed "The Ghost and Mr. Chicken (1966)."