The 18th century was the golden age for a type of self-moving mechanical device called the automaton, and Vaucanson was the era's most famous creator. When he was 18 years old, Vaucanson built automata that served dinner and cleared tables for guests. Later, he built a breathing, flute-playing automaton, as well as one that could play the fife-and-drum. But Vaucanson's most popular creation was undoubtedly the defecating duck he built in 1733-1734.
Vaucanson's gold-plated copper duck could not only move and quack like a duck, but it could eat like one, too. The duck swallowed kernels of grain, and as Vaucanson explained, digested the food in its chemical stomach, then poop them out through a mechanical sphincter.
(L) Vaucanson, from Illustrierte Geschichte der Medizin/Richard Toellner (M) Photograph of lost original or imitation in ruined state/Musée du Conservatoire National des Arts et Métiers, Paris
(R) Reproduction in Musée des Automates de Grenoble
There was no shortage of viewers, who each paid a week's wage to see the duck. Voltaire even mused that "without the shitting duck of Vaucanson, you will have nothing to remind you of the glory of France."
After Vaucanson became a rich man, he sold all of his automata to collectors and the duck was soon lost to history ... until it was found languishing in a pawnbroker's attic more than a hundred years later. The discoverer brought the duck to a magician named Jean-Eugène Robert-Houdin (who's now considered the father of modern magic, and from whom Houdini took his name). Robert-Houdan found out that the duck was actually a clever hoax: Vaucanson had built a special chamber inside it to store a preparation of dyed green breadcrumbs that people thought was duck poop!
Source: Edison's Eve: A Magical History of the Quest for Mechanical Life by Gaby Wood