Referring to the project as Damn Cat, 15 Jan 1963 DV announced that Walt Disney Productions had purchased screen rights to Undercover Cat, a crime fiction novel by husband and wife Mildred Gordon and Gordon Gordon, which was set to be published later that year. The feline protagonist, “Pancho,” was monikered “Damn Cat” in the book, and DV rumored that Disney would most likely change the film title to Darn Cat. Just over six months later, a 29 Jul 1964 DV news item reported that British child actress Hayley Mills was preparing to begin pre-production for That Darn Cat on 1 Sep 1964. The film marked her sixth picture for Disney.
       Principal photography began 12 Oct 1964, according to a 14 Oct 1964 Var listing, but a conflicting Var production chart two days later indicated that the filming start date had been pushed back to 19 Oct 1964. That date was confirmed in an 11 Nov 1964 Var article, which stated that shooting was currently underway at Disney soundstages in Burbank, CA. The picture had a forty-week production schedule, and was budgeted at over $1 million. The Siamese feline star, “Syn Cat,” was reportedly trained by William R. Koehler for over three months before filming began. Syn Cat was previously credited with the starring role of “Tao” in Disney’s The Incredible Journey (1963, see entry), but was not listed onscreen in That Darn Cat. A 3 Dec 1964 LAT article noted that production was nearing conclusion for the human actors, but eighteen cats were scheduled to remain on set until Jun 1965, with each animal performing a separate stunt.
       Disney released a remake in 1997.