A clockwork monkey is a magical novelty item sold at Weasleys' Wizard Wheezes. It is described as a mouse-colored, clockwork monkey that perpetually climbs up and down a silver chain. As an item intended to promote the brand, the monkey is dressed in a miniature set of purple and orange Weasleys' Wizard Wheezes robes. This item was prominently displayed in the shop's window, serving as both a product for sale and an eye-catching advertisement for the establishment at Number 93, Diagon Alley. This is the most significant appearance of a monkey, albeit a toy one, in the original novels.
The primary function of the clockwork monkey is amusement. As a “clockwork” toy, its continuous motion is likely powered by simple enchantments rather than traditional Muggle mechanics. It serves as an example of the kind of whimsical and inventive magical merchandise created by the Weasley twins. Its placement in the shop window was designed to attract customers and showcase the lively, fun-loving nature of the store's products.
The clockwork monkey was invented by Fred and George sometime after they left Hogwarts School of Witchcraft and Wizardry in the spring of 1996. It was one of the many original products they developed for the grand opening of their joke shop. Harry Potter, Ron Weasley, and Hermione Granger observed the monkey in the shop window during their visit in August 1996, shortly before the start of their sixth year.
The clockwork monkey plays a minor but memorable role as a piece of world-building. Its presence in the window of Weasleys' Wizard Wheezes is one of the first things Harry Potter notices upon visiting the shop for the first time. The monkey, along with the other vibrant and chaotic products, establishes the shop as a beacon of humour, defiance, and normality. This stands in stark contrast to the growing fear and gloom that had settled over the rest of Diagon Alley following the public return of Lord Voldemort.