Nargles are creatures that are spoken of in the Harry Potter series, yet their physical form or any solid evidence of their existence remains absent throughout the books. Luna Lovegood is the only character in the series known to believe in their existence, and she frequently mentions them as mischievous and thieving creatures that are often blamed for anything missing or amiss, much like gremlins. Nargles are said to live in mistletoe and are known to infest it. According to Luna, they have light purple to black skin, two thin arms and legs with long fingers and toes, bat-like ears, large white eyes, pointy noses, and sharp teeth. Nargles are mischievous trouble-makers that make messes and steal things, and they dont trust anyone but themselves, which makes them impossible to befriend. They live anywhere where they can make trouble and often live in mistletoe to attack people kissing underneath. Nargles are classified as XX, which is the second level of dangerousness, and they can bite people, although they rarely do. However, they are allergic to butterbeer and Dirigible Plums, and if they touch either, they will turn light green and be weakened.

It is unclear whether Nargles actually exist in the wizarding world, as Luna Lovegood is the only source of information about these creatures, and her reliability as a source is debatable. Rowling never directly confirms or denies their existence in the wizarding world, and given their very inconspicuous nature, Nargles may not even exist. However, even if Nargles may not exist within the world of Harry Potter, they hold a significant symbolic meaning. They reflect Luna’s unique perspective and her refusal to abide by others’ views of what is “real” or “possible” . Luna’s belief in Nargles, despite the skepticism of her peers, represents her acceptance of the unknown and the unproven.