In the series of books created by J. K. Rowling, what animal form did Harry Potter's Patronus take?
And the answer: Stag.
In the Wizarding World created by J. K. Rowling, a Patronus is a shield or a protector against Dementors, who attack humans by feeding on their hope and happiness. Harry Potter is one of the youngest wizards to cast a corporeal Patronus, which takes the same shape as his father's.
While some of the most advanced wizards struggle to cast a Patronus, Harry Potter is able to cast the spell at just 13 years old. A Patronus, as Professor Lupin explains in Prisoner of Azkaban, is a positive force that can effectively fight off Dementors. A Patronus can not feel despair, as humans can, and thus is a perfect shield against soul-sucking Dementors.
A Patronus has two forms: corporeal and non-corporeal. A non-corporeal Patronus takes the form of a wispy, silver projection of an animal, while a corporeal Patronus is clearly defined and often very bright. The ability to cast one or the other depends on the skill of the witch or wizard— yet young Harry was able to conjure a dazzling corporeal Patronus to save his friend Hermione and uncle Sirius Blacks' lives.
A Patronus is conjured by thinking of a very happy, powerful memory. Each witch and wizard has their own unique Patronus who will appear if the words are uttered in tandem: "Expecto patronum." Try it for yourself!
Learn more about Harry Potter lore and Patronuses here.