Harry Potter and the Prisoner of Azkaban introduced the idea of the Patronus charm in Harry Potter canon. Since then, Patronuses have become one of the most iconic elements of the entire franchise. The spell itself, Expecto Patronum, is the only tool to combat the soul-sucking beings known as Dementors. These charms, if powerful enough, come in the form of an animal associated with the user's happiest memory.
The only snag in regards to conjuring a Patronus is their inherent difficulty. Few wizards have mastered it, but as shown in the series, with hard work it's possible. Looking back through both the films and films, here is every known character's Patronus in Harry Potter.
Boar - Ernie Macmillan
Ernie Macmillan might not be a familiar name to fans of the films, but for book readers, he is a quintessential background character at Hogwarts. This Hufflepuff is one of the most outspoken students at Hogwarts School of Witchcraft and Wizardry. Always needing to share his opinion, Ernie is stubborn and proud, often at his downfall.
It is appropriate then that his Patronus would take the form of a boar. This animal is often used in literature to symbolize many of the traits that are inherent to Ernie Macmillan. Audiences were introduced to Ernie's Patronus at the Battle of Hogwarts in Harry Potter and the Deathly Hallows. Ernie and a few of his classmates used the charm to combat an attack from a group of dementors.
Lynx - Kingsley Shacklebolt
Kingsley Shacklebolt is one of the most valued members of the Order of the Phoenix. A powerful Auror, he was instrumental during the Second Wizarding War and in the protection of Harry Potter. Kingsley innate leadership skills eventually secured him the position of Minister of Magic post-the Battle of Hogwarts.
The first appearance of Kinglsey's Patronus was also during The Deathly Hallows. Although it differs in the film, appearing as a noncorporeal, Kingsley's Patronus takes the form of a Lynx in the original book. This predator Cat materialized at Bill and Fleur Weasley's wedding to warn of the fall of the Ministry of Magic.
Goat - Aberfoth Dumbledore
In The Deathly Hallows, J.K. Rowling began revealing the real history of Dumbledore's family. One of the most instrumental figures to come out of this reveal was Aberforth Dumbledore, Albus' brother. Aberforth was the barman at The Hog's Head pub in Hogsmeade village, where Harry, Ron, and Hermione eventually sneak into Hogwarts near the finale.
Once again, it is in this book that another character's Patronus appeared. Aberforth cast the charm and produced a Patronus in the form of a goat, referencing his affinity for the animal.
Swan - Cho Chang
The first romantic interest for Harry Potter, Cho Chang remains a bit of a forgotten character near the end of the series. That being said, she held an essential role through the middle chapters of the franchise. Particularly in The Order of the Phoneix, Cho was nearly a lead character.
During this time, Cho took part in the rise of Dumbledore's Army, where many young Hogwarts students first conjured a Patronus. It was then when Cho first conjured a corporeal Patronus in the form of a Swan.
Fox - Seamus Finnegan
Seamus Finnegan is another quintessential background player throughout the series. His role has carried in terms of respectability. More often than not he is a loyal friend, but he was easily swayed against Harry during The Order of the Phoenix. Eventually, though, their friendship mended, and Seamus began training alongside Dumbledore's Army.
During Harry's teaching, Seamus was able to conjure a Patronus in the form of a fox, albeit for a short time. Perhaps the redness of a fox is meant to symbolize Seamus' tendency towards pyrotechnics?
Weasel - Arthur Weasley
The most underrated of Harry's father figures, Arthur Weasley is a sincerely kind and supportive individual. Arthur has had to put it with a lot, from classism to nearly being murdered by possessed boa. Throughout it all though, he has been able to keep a smile and carry on. Because of his incredible characterization, it's a bit annoying that his Patronus is nothing more than a pun.
In The Deathly Hallows, Arthur sends his Patronus to Grimmauld Place when the trio is using it as a hideout. When it appears before them, it takes the form of a Weasel. Weasley and Weasel. Seriously J.K.?
Wolf - Remus Lupin and Nymphadora Tonks
The form that a Patronus chooses to take is often considered an incredibly individual choice, tied to the characteristics of that who conjured it. Usually, though, a Patronus will change its shape if the witch or wizard feels deeply connected with another person. This is precisely what happened between Remus Lupin and Tonks.
Lupin's Patronus often took the form of a wolf, for obvious lycanthrope related reasons. Tonks, on the other hand, had a completely different Patronus form before she fell in love with Lupin. Once the two came together, her Patronus took on the same wolf shape as her husband.
Cat - Minerva McGonagall and Dolores Umbridge
This doubled pair shares a Patronus for purely coincidental reasons. Dolores Umbridge and Professor McGonagall both share the same cat shaped Patronus. Audiences know that McGonagall is an Animagus, a being who can take the form of an animal, and takes the shape of a tabby cat.
Umbridge on the other hand purely just favors the animal, as shown through her extensive feline plate collection. The two also hold a surprising amount of similar characteristics. Both are strong-willed and independent; one just so happens to be a sadistic racist towards centaurs.
Hare - Luna Lovegood and Nymphadora Tonks
It is fitting that two of the most eccentric characters in the entire Harry Potter franchise would share the same Patronus. Tonks and Luna Lovegood both conjured Patronus in the shape of a hare. Luna first used the charm during The Order of the Phoneix when Harry taught Dumbledore's army how to use the spell.
Tonks on the other hand quickly changed hers, as previously noted, to the form of a wolf. The hare was far more fitting to her as an individual, but the change to a wolf clearly showed her deep, and occasionally unrequited, love for Remus
Horse - Ginny Weasley
A character that never got her due in the films was the incredible Ginny Weasley. Ginny had far greater characterization the novels, presenting her as a fiery and independent spirit. Through all of her interactions with other characters, particularly her romantic ones in The Half-Blood Prince, Ginny was always in control and would never be tied down.
Appropriately, her Patronus took the form of a horse. In the film version of Order of the Phoneix, this horse was incredibly wildly. A free spirit such as Ginny Weasley deserves no better Patronus than that.
Magpie - Fred and George Weasley
No pair is as inseparable as Fred and George Weasley. These Gryffindor twins were the most important people in each other's lives. Fittingly they shared the same Patronus form. The Weasley twins conjured Patronus that took the shape of a Magpie, a small but loud crow-like bird.
In English slang, to call someone a Magpie is to comment on their boisterous nature. Seeing as Fred and George were the class clowns of Hogwarts, it's fitting that their Patronus would reflect their attention seeking behavior.
Non-Corporeal - Neville Longbottom and Remus Lupin
As stated, the Patronus charm requires intense focus and self-awareness. For wizards who struggle in either one of the departments, the Patronus charm becomes a near impossibility. Neville Longbottom is the perfect example. Neville struggled incredibly to conjure a Patronus charm that when he finally did it held no discernable shape (much like Harry in his early lessons with Lupin). Neville can produce the spell, but not enough to give it animal form.
An interesting point on noncorporeal Patronus though is Lupin. Although his Patronus naturally takes the form of a wolf, Remus suppresses this and chooses to produce a noncorporeal due to the shame of his condition.
Phoenix - Albus Dumbledore
Unlike his somewhat grounded brother, Albus Dumbledore is quite the mystical and unconventional character. Dumbledore plays the role of the wise sage for much of the series. He holds a sense of otherworldly knowledge absent from most other characters. As such, it only fits that Dumbledore's Patronus would be the only one to take on the shape of a fantastic beast.
Mirroring his pet choice, Albus Dumbledore's Patronus appears as a Phoenix. This reincarnating fowl is a favorite of Dumbledore, both as a companion and as a title for his underground rebellion. Beyond mysterious, this Patronus is one of the most fitting pairings for any character on this list.
Doe - Severus Snape and Lilly Potter
There is no doubt that one of the biggest reveals in the entire Harry Potter franchise was the truth behind Severus Snape's intentions. As shown in The Deathly Hallows, Snape had fallen in love with Lilly Potter at a young age. After her death, he swore allegiance to Dumbledore and to protect Harry's life.
Although the morality surrounding many of Snape's decisions are debated to this day, there is no denying that he cared deeply for Lilly Potter. So much so, that his Patronus soon morphed to mirror hers. The two both produced a Patronus of a Doe, which eventually leads Harry to discover the sword of Gryffindor.
Jack Russell Terrier - Ron Weasley
The fantasy genre is full of iconic sidekicks. If Harry Potter is the Frodo of his story, Ron Weasley is the dutiful Samwise. Rone has remained Harry's best friend from day one. Sure, they had a couple of bumps along the way, but like every friendship, Ron was always there at the end of the day. Ron's Patronus fulfills this role perfectly.
When learning alongside his classmates in Dumbledore's Army, Ron conjured his Patronus in the form of a dog. Specifically, Ron's Patronus was a Jack Russell Terrier. As a breed, Terriers are fiercely loyal and protective. As Harry's best friend, what could be a better fit than man's best friend?
Otter - Hermione Granger
Out of all of the characters in Harry Potter, J.K. Rowling has stated that Hermione is the one she identifies with most. Out of all of the characters, Hermione's journey as a young adult closely mirrors Rowling's. It would make sense then that when creating each character's Patronus, Rowling would make Hermione's incredibly personal.
In The Order of the Phoneix, Hermione conjured her Patronus for the first time, taking the form of a river otter. Rowling revealed on Twitter that otters are her favorite animal. Who else deserves that honor than Hermione Granger herself?
Stag - Harry and James Potter
The first time readers learned of the concept of the Patronus was through Harry's experience with dementors. During this struggle, Harry eventually gained the ability to perform the charm on a scale large enough to combat hundreds of dementors at once. This speaks primarily to his deep connection with his late parents.
Both Harry, Lilly, and James share deer as their Patronus. Harry and James specifically both conjured stags as their protective charms. There are no other characters which share the same Patronus form animal as do the Potters.