Harry Potter - PolyJuice Potion Heat Changing Coffee Mug Polyjuice Potion is a potion that allows the drinker to assume the form of someone else. It's a complicated and challenging potion that even adult witches and wizards struggle to brew correctly. The potion is incredibly advanced and has two separate parts that contain steps for each part, when brewing is complete the potion has to stew for a month before usage Specifics: Polyjuice potion vanishes with heat. Dimensions: 10cm (approx. ) Hand wash only. - Harry Potter - PolyJuice Potion Heat Changing Coffee Novelty Mug