The Patronus holds a special place in the Harry Potter mythology.

As Professor Lupin explains in Harry Potter and The Prisoner of Azkaban, a Patronus is "a kind of Anti-Dementor – a guardian which acts as a shield between you and the Dementor". It’s also "a kind of positive force, a projection of the very things that the Dementor feeds upon – hope, happiness, the desire to survive – but it cannot feel despair, as real humans can, so the Dementors can’t hurt it". So Harry's own Patronus takes the form of a stag, just like his father's, while Hermione's is an otter. Now, the official Pottermore site allows you to conjure your own Patronus. You have to be a registered member of the site (it only takes a minute to join).  It's a 3D experience that asks you to make a series of choices, based on a prompts and questions written by J.K. Rowling herself. Users will summon a happy memory to get things started, and then respond "to a series of short, time-sensitive multiple-choice options on screen, users are able to discover and ultimately be presented with their Patronus – which has been chosen for them using J.K. Rowling’s own secret algorithm." My one is a brown bear: Take the quiz and discover your own one by clicking through to Pottermore here. Cover image via Warner Bros.