A Nose-Biting Teacup appears, at first glance, to be an ordinary porcelain teacup. However, it is magically bewitched. Its key feature is a set of tiny porcelain jaws, which are not immediately obvious. The cup is designed to look harmless to an unsuspecting victim. One such teacup, discovered by Harry Potter in the Room of Requirement, was stored in a box.
The primary magical property of a Nose-Biting Teacup is its ability to animate and attack. When a person attempts to take a drink, the teacup snaps its jaws and bites them on the nose. This enchantment serves no practical purpose beyond being a startling and humorous prank. It is a popular item among young witches and wizards looking for a laugh at someone else's expense. The effect is more surprising than genuinely harmful, fitting its classification as a joke item.
The Nose-Biting Teacup appears as a background object that helps to build the colourful and whimsical nature of the magical world.