Ghouls

A ghoul is a magical creature generally regarded as harmless, though often considered a noisy pest by the wizarding families they live with. They are unintelligent, slimy creatures that typically inhabit the attics or barns of wizarding homes. Despite their rather grotesque appearance, they pose no real threat and are officially classified as “Boring” by the Ministry of Magic. The most notable ghoul in the series resided at The Burrow and played a small but crucial role in a deception to protect Ron Weasley during the Second Wizarding War.

Ghouls are described as being ugly, slimy creatures with buck-teeth. The ghoul living with the Weasley family was also noted to have long, spindly arms. They are simple-minded and primarily communicate through moans, groans, and loud banging noises, often when they feel their environment is too quiet. Their diet consists of insects such as spiders and moths. While they may occasionally throw objects, their behavior is more of a nuisance than a genuine danger.

The most prominent example of a ghoul is the one that lived in the attic of The Burrow. This ghoul was a familiar presence to the Weasley children, known for groaning and banging on the pipes whenever the house fell silent. During the Second Wizarding War, this ghoul became an essential part of a plan to conceal Ron Weasley's absence while he was away hunting Horcruxes with Harry Potter and Hermione Granger. The Weasleys transfigured the ghoul to resemble Ron suffering from a severe case of Spattergroit, complete with pustules, and installed it in Ron's bedroom. The ghoul's purpose was to moan and remain in bed, fooling any Ministry of Magic officials who might check on the Weasley household. According to Arthur Weasley, the ghoul seemed to enjoy the attention and the change of scenery. The existence of ghouls as a common, if minor, problem is also suggested by the title of one of Gilderoy Lockhart's books, Gadding with Ghouls.

Ghouls are not known to possess any magical abilities of their own. Their status as magical creatures stems from their existence within the magical world rather than any inherent powers. The Ministry of Magic's Department for the Regulation and Control of Magical Creatures assigns them a classification of XX, which designates a creature as “Boring” and harmless. They are, however, susceptible to magic cast upon them, as demonstrated when the Weasley ghoul was successfully transfigured to resemble a sick Ron Weasley.

Ghouls often live in a state of tolerated cohabitation with wizarding families. The Weasley family treated their ghoul as a familiar, if sometimes annoying, part of their home. For households where a ghoul becomes an unwanted presence, the Ministry of Magic maintains a Ghoul Task Force within the Department for the Regulation and Control of Magical Creatures to handle their humane removal from Muggle or wizarding dwellings. (Pottermore)

The term “ghoul” is derived from the Arabic ghūl (غول), which in Middle Eastern folklore refers to a monstrous, demonic entity that robs graves and consumes human flesh. This folkloric origin presents a stark contrast to the depiction of ghouls in the Harry Potter universe, where they are portrayed as simple, non-threatening creatures.

• J.K. Rowling has stated that the mental image of the ghoul in Ron's pyjamas was one of her favourite visual gags in Harry Potter and the Deathly Hallows. (J.K. Rowling interview)
• In the film adaptation of Harry Potter and the Deathly Hallows - Part 1, the ghoul is briefly shown in Ron's bedroom as part of the Spattergroit ruse. It is depicted as a pale, gaunt creature with large eyes, loosely fitting the description from the novel. (film)