The sinking of the yacht and several shots of the cat in the ocean were filmed in Greydon Clark's swimming pool.
75,000 dollars of the film's 200,000 dollar budget went to the salaries for George Kennedy, Alex Cord, and Clu Gulager.
The same two stock "meow" sound effects are repeated in various combinations throughout the movie, whenever the animal is supposed to make a noise.
An earlier draft of the script had a rat instead of a cat in it.