If the Transformation lessons don't work out right and you don't happen to be an Animagus, there's basically only one way for a young wizard to transform their appearance: Polyjuice Potion. With its help, you can transform into any other person, as long as you have one of their hairs or another “piece” of them. Harry, Hermione and Ron tried it out themselves in second year, when they secretly brewed the complex potion in order to find out the secret of the heir of Slytherin.

With its impressive effect and its important role in Harry, Ron and Hermione's story, the Polyjuice Potion is a great memory of the world of Harry Potter – especially in the shape of this officially licensed Harry Potter Polyjuice Potion Glass. The unique colour warns of unsafe use, and a label identifies it as Polyjuice Potion – from Horace Slughorn's personal stock, no less. The other side of the glass reads “Hogwarts Apothecary Department” right under the Hogwarts crest.

Of course, you don't have to put Polyjuice Potion in the glass – it can be pretty difficult to get your hands on Boomslang skin and bicorn horns these days. Coke, juice, maybe a little Butterbeer or Firewhiskey will do just as well.

But if you do use Polyjuice Potion: Make sure that your extra ingredient is not a cat hair. ;)