Arnold the Pygmy Puff

Arnold is a purple Pygmy Puff belonging to Ginny Weasley. As a miniature, fluffy magical beast, Arnold serves primarily as Ginny's pet, which she purchased from her brothers' shop, Weasleys' Wizard Wheezes. He is a minor character featured in Harry Potter and the Half-Blood Prince, representing the commercial success of Fred Weasley and George Weasley's joke products and highlighting Ginny's playful and affectionate nature.

Arnold was purchased by Ginny Weasley in Diagon Alley from Weasleys' Wizard Wheezes in August of 1996, prior to the start of her fifth year at Hogwarts School of Witchcraft and Wizardry. She introduced Arnold to Harry Potter and Ron Weasley aboard the Hogwarts Express on their way to school. During the journey, Arnold was seen sitting on Ginny's shoulder, occasionally letting out a squeak. Throughout the school year, Arnold remained Ginny's constant companion. He was often seen perched on her shoulder in the Gryffindor Common Room. Ginny's affection for him was evident; when she joked with her brother Ron about practicing her Bat-Bogey Hex, she noted that Ron was a much bigger target than her tiny pet Arnold. The fate of Arnold following the events of the Second Wizarding War is unknown.

Arnold is described as a tiny, fluffy, purple Pygmy Puff. Like other members of his species, which are miniature Puffskeins, he is perfectly spherical and covered in soft fur. His personality appears to be docile and affectionate, as he is content to ride on Ginny's shoulder and accept food from her, such as a piece of breakfast cereal. He communicates through small squeaks.

As a Pygmy Puff, Arnold is a magical beast. While his specific abilities are not detailed in the novels, Puffskeins are known scavengers that eat anything from leftovers to spiders and will emit a low humming sound when they are content. It is presumed Arnold shares these basic magical creature traits. He does not display any unique or powerful magical skills, functioning solely as a domestic pet.

As a pet, Arnold does not have any known possessions of his own.

• Ginny Weasley: Arnold is Ginny's beloved pet. She chose his name and cares for him affectionately, carrying him with her around Hogwarts.
• Fred Weasley and George Weasley: The Weasley twins are the breeders and sellers of Pygmy Puffs, making them Arnold's creators in a sense. Their product's popularity allowed Ginny to purchase Arnold.
• Ron Weasley: Ron appeared to be somewhat exasperated by Arnold, especially when Ginny used the tiny creature as a point of comparison when threatening to hex him.
• Harry Potter: Harry's interactions with Arnold are minimal, though he observes the pet with some amusement on the Hogwarts Express.

The name Arnold is of German origin, derived from the elements arn (“eagle”) and wald (“power” or “ruler”). There is no canonical explanation for why Ginny chose this name. The choice of a strong, traditional human name for a tiny, fluffy, purple creature creates a humorous contrast, which is characteristic of the Weasley family's sense of humour.

• Arnold the Pygmy Puff appears briefly in the film adaptation of Harry Potter and the Half-Blood Prince. He is seen in the Weasleys' Wizard Wheezes shop, where Ginny is holding him. (film)
• The Pottermore website confirms that Pygmy Puffs are a miniature breed of Puffskein developed by Fred Weasley and George Weasley for their shop. (Pottermore)