Amongst the changes that Vigo made to the original script was replacing Père Jules' pet dog with over ten alley cats supplied by the Society for the Prevention of Cruelty to Animals. Vigo's father had been fond of such cats and Vigo's childhood homes were often overrun with stray cats. During the scenes where Père Jules plays his phonograph, the cats would become immediately fascinated by the phonograph and surround it whenever it played music. Vigo quickly assembled his crew and shot footage of the cats listening to the music and sleeping inside the loud speaker. Simon later adopted the kitten that rested inside the phonograph horn. Vigo also visited local flea markets in Saint-Ouen and the scrap metal market on Boulevard Richard-Lenoir to find props for Père Jules' collection of artifacts from around the world.