As explained on the Pottermore page, a Patronus is a form of advanced magic in which the witch or wizard casting the spell draws upon their happiest memories to produce a kind of shield to help protect themselves from Dementors, the guardians of the wizarding prison, Azkaban.

You know your Harry Potter house—both Hogwarts and Ilvermorny. You’ve chosen your wand. (Or rather, it’s chosen you.) Now, it’s time to discover your Patronus.

A lynx is a medium-sized wildcat, indigenous to Eurasia and North America, generally known for its reflective eyes, short tail and tufted black hair on its ears.[1]

It is a corporeal form of the Patronus Charm.[2] Kingsley Shacklebolt's Patronus takes the form of a lynx. In 1997, it appeared to the guests at the Wedding of William Weasley and Fleur Delacour and warned them of the Fall of the Ministry of Magic.[3]

Wondering who else has your Patronus? From Harry’s stag to Hermione’s otter, here are some of the more memorable Patronuses featured in Harry Potter.

J. K. Rowling surprised fans Thursday morning by revealing the latest feature of Pottermore—the official digital publisher for all things Potter—a quiz that allows fans of the series to discover their very own Patronuses.

When spell casters are able to successfully summon a corporeal Patronus—as opposed to some silver vapor—it often takes the shape of an animal (or even magical creature) unique to the witch or wizard. So far, users of the feature have reported receiving everything from a hedgehog to a unicorn. Rowling even revealed hers is a white swan.