Many pets in the series are ordinary animals with magical properties. Owls, for example, deliver mail. Only creatures that exist exclusively in the magical world are listed below.
The Department for the Regulation and Control of Magical Creatures classifies magical creatures on a scale from X to XXXXX as follows (according to page xxii of Fantastic Beasts):
In Harry Potter and the Chamber of Secrets, a basilisk was the monster that inhabited the Chamber of Secrets. When student Tom Marvolo Riddle, who later becomes Lord Voldemort, opened the chamber the Basilisk killed Myrtle, and then hibernated for fifty years. During the events of the book, it is set loose again by a Horcrux of Voldemort, and attempts to kill several Muggle-borns, but due to sheer luck all its victims are merely petrified. The Horcrux commanded Ginny Weasley to kill all the school roosters, remarked upon by Hagrid. When Harry discovers the existence of the chamber and of its location, Riddle reveals his identity and sets the basilisk loose upon Harry while Ginny's life force ebbs away. Fawkes appears to assist Harry, blinding the basilisk with its talons and carrying the Sorting Hat; Harry pulls the sword of Godric Gryffindor from that hat, and uses it to impale the basilisk's head, killing it.
The basilisk's fangs and its venom absorbed by the sword of Gryffindor proved instrumental for destroying most of Voldemort's Horcruxes. In Harry Potter and the Deathly Hallows, after losing the sword of Gryffindor to Griphook, Ron Weasley and Hermione Granger go to the chamber and pull some fangs out of the Basilisk's skull, and use one to destroy Helga Hufflepuff's cup.
Characters and their Boggarts:
The films depict the centaurs with very bestial, animalistic facial features; however, the obvious attraction of Hogwarts' female population to Firenze suggests that the books depict centaurs in terms that are more classical.
Named Centaur characters:
Being blind, Dementors sense and feed on the positive emotions, happiness and good memories of human beings to move around, forcing them to relive their worst memories. The very presence of a Dementor makes the surrounding atmosphere grow cold and dark, and the effects are cumulative with the number of Dementors present. Despite their attachment to human emotion, Dementors seem to have difficulty distinguishing one human from another, as demonstrated by Barty Crouch Jr's escape from Azkaban, wherein they could detect no emotional/mental difference between the younger Crouch and his mother. In addition to feeding on positive emotions, Dementors can perform the Dementor's Kiss, where the Dementor latches its mouth onto a victim's and sucks out the person's soul. The victim is left as an empty shell, incapable of thought and with no possibility of recovery. It is believed that existing after a Dementor's Kiss is worse than death. The Ministry of Magic occasionally uses this as a punishment, such as on Barty Crouch Jr. One way to shield oneself from Dementors is to use the Patronus Charm to drive them away. Chocolate is an effective first aid to mild cases of contact. Dementors are invisible to Muggles, but affect them in the same way. While at least one Squib in the series has claimed to see a Dementor, Rowling has stated that this was a lie and that Arabella Figg noticed it because of the effect it had on her. Rowling has likened the effect of a Dementor to the human ailment known as depression, which the author has herself experienced. She describes it as "that absence of being able to envisage that you will ever be cheerful again. The absence of hope. That very deadened feeling, which is so very different from feeling sad."
Harry first encounters Dementors during the beginning his third year of school, when they are sent to guard Hogwarts against Sirius Black, who has recently escaped Azkaban. Harry, whenever he gets near one, is forced to relive his worst memory: hearing the last moments of his parents' lives before they are murdered by Voldemort, which begins with Harry hearing his mother screaming. To overcome the Dementors, Harry asks Remus Lupin for assistance. Lupin teaches Harry the Patronus Charm, albeit with some difficulty. In Harry Potter and the Order of the Phoenix, Harry and his cousin Dudley Dursley are ambushed by two Dementors sent secretly and illegally by Dolores Umbridge. At the end of Harry Potter and the Order of the Phoenix, the Dementors of Azkaban stage a mass revolt against their employers to join Voldemort, as he can provide them with more humans to feast upon. In Harry Potter and the Deathly Hallows the Ministry, under the control of Voldemort, uses Dementors to punish those who are Muggle born for no other reason than because Voldemort hated Muggles and Muggle-borns. The Dementors also take part on Voldemort's side during the Battle of Hogwarts. After the appointment of Kingsley Shacklebolt to the position of Minister, Dementors are removed from Azkaban, and the Ministry contain them by limiting their numbers.
In the Harry Potter universe, only wizards can become ghosts. As Nearly Headless Nick explained to Harry, "Wizards can leave an imprint of themselves upon the earth, to walk palely where their living selves once trod ... I was afraid of death. I chose to remain behind. I sometimes wonder whether I oughtn't have ... Well, that is neither here nor there ... In fact, I am neither here nor there..." Despite having chosen their afterlives, many ghosts appear quite unhappy; they bemoan their not-quite inability to eat, and many are described as gloomy. They also appear to have an attraction to the morbid and melancholy.
Ghosts are very sensitive about their condition. When the Ministry initially classified them as "beings", i.e., sentient creatures with full legal rights, they claimed that the term was insensitive when they were clearly "has-beens". The Ministry's Department for the Regulation and Control of Magical Creatures therefore comprises a separate "Spirit Division". The Ministry's spirit division apparently controls the activities and haunting locations of troublesome ghosts. Myrtle was forced to go back and haunt the place of her death (Hogwarts) after she had disrupted the wedding of Olive Hornby, a girl who had teased her at school.
Named Ghost characters:
Voldemort has employed giants in his attacks, after convincing them that he can offer them a better life. Hagrid revealed in Harry Potter and the Order of the Phoenix that he and Madame Maxime went on an Order mission to ask the Giants to take part in the war against Voldemort; however Karkus the Gurg was killed by other Giants, thus Hagrid and Maxime were forced to introduce themselves to Golgomath, the new Gurg. Several Death Eaters are sent by Voldemort in a mission too to get the Giants into the Dark Lord's side. Giants took part in the Battle of Hogwarts in the end of the series, mostly fighting for Voldemort.
Relations between goblins and wizards have been strained for centuries from misunderstandings on both sides, sometimes leading to violence in the form of goblin rebellions and riots. Along with house-elves, goblins seem to occupy positions as second-class citizens in the Wizarding world. The goblins remain a neutral force during the Second Wizarding War, siding with neither Voldemort or the opposition to him, claiming that it is "a wizard's war". In some cases, a state of friendship exists between certain wizards and goblins (particularly Bill Weasley, who works as a Curse Breaker for Gringotts Bank), and there have even been some instances of goblin-wizard interbreeding (Professor Flitwick has distant goblin ancestry, which likely accounts for his small size).
Named Goblin characters:
House-elves possess their own forms of powerful magic, distinct from that used by wizards and witches, which they generally use in the service of their masters. This magic can be used without the permission of their masters, or even against their orders, though such disobedience obliges them to punish themselves in various painful ways. Among other things, this magic allows house-elves to travel instantly from place to place, in a manner similar to apparition; they are able to do this even within the boundaries of Hogwarts and other places where Anti-Apparition and Anti-Disapparition charms are in effect, preventing human apparition and disapparition. House-elves can, however, use side-along apparition to transport humans. The full nature of the elves' magic is never fully disclosed, but it seems to be quite formidable. Along with the ability to apparate anywhere at any time, both Dobby and Kreacher demonstrate that they can overpower wizards when necessary. In Harry Potter and the Chamber of Secrets, Dobby forcefully repels Lucius Malfoy while protecting Harry Potter. Later, in Harry Potter and the Deathly Hallows, Kreacher is ordered by Harry to capture Mundungus Fletcher and bring him to 12 Grimmauld Place, a task that he accomplishes within a few days, even though, as Kreacher puts it, "He has many hidey-holes and accomplices."
It is never made clear whether house-elves are bonded primarily to the families they serve or to their homes. Ron Weasley comments that he wishes his family were rich enough to afford a house with a house-elf, suggesting that they are linked to houses rather than to families (very much like serfs in the Middle Ages). In addition, when the ownership of Grimmauld Place passes to Harry in Harry Potter and the Half Blood Prince, Harry's status as the rightful owner of the house is confirmed when the house-elf Kreacher grudgingly obeys his commands. On the other hand, in Harry Potter and the Goblet of Fire, it is said that a house-elf who has been freed is normally told to find a new family to serve. There is an Office of House-Elf Relocation at the Ministry of Magic.
House-elves are unendingly loyal to their human families; so much so, that Dobby, who served the Malfoy family, attempts to punish himself each time he utters a negative remark about his former masters even after freed. However, he is able to overcome it more as time passes, even going so far as to defiantly tell Bellatrix Lestrange that none of the Malfoys are masters over him. According to Kreacher, a house-elf's strongest law is the master's bidding; however, while house-elves must obey their masters whatever their personal feelings may be, they are far from mindless automata. House-elves have been known to disobey the rules (usually by finding, when necessary, loopholes in orders that allow for unintended interpretations) to protect themselves or their friends. Because of their docile, obedient natures, some families abuse their house-elves. Dark wizard families in particular seem to make a habit of bullying and maltreating house-elves; the Malfoys forced Dobby to slam his own ears in the oven door or iron his hands if he attempted to disobey them; the Black family had a tradition of decapitating house-elves who were too old to carry a tea tray, then placing their stuffed and mounted heads on a wall.
Most house-elves would be devastated if freed, for it would mean that they had failed to serve their masters properly; but some (like Dobby) enjoy being free. Though he summons the courage to request payment when he is hired on at Hogwarts, even Dobby does not want to be paid too much. Most people in the wizarding community are unwilling to pay a house-elf, as this would obviate the point of having one. Indeed, most house-elves seem to regard paid service as a disgrace to their race.
Thestrals have fangs and possess a well-developed sense of smell, which will lead them to carrion and fresh blood. According to Hagrid, they will not attack a human-sized target without provocation. Their wings are capable of very fast flight for at least several hours at a time, though they usually spend their time on the ground, and they have an excellent sense of direction. The breed is at least semi-domesticable, given a willing trainer. Thestrals can be used to pull loads, and make a serviceable if very uncomfortable mode of transportation for someone with enough nerve.
Hogwarts has a herd in the nearby Forbidden Forest and primarily uses them to pull the carriages that transport students to and from the Hogsmeade train station. They are introduced to Care of Magical Creatures students in the fifth year by Hagrid — in the same year that Harry becomes able to see them after witnessing the death of Cedric Diggory, having previously thought that the carriages moved on their own. Thestrals are featured in the Battle of Hogwarts at the end of Harry Potter and the Deathly Hallows, seen attacking Death Eaters. In the same book, it is revealed that the Elder Wand has a core of Thestral hair, although no other wands are known to use Thestral hair as a core.
As an attempt to discourage Harry from returning to Hogwarts, Dobby begins to intercept the letters that Harry's friends sent him. Dobby then appears at Privet Drive to warn Harry and tell him of the danger of returning to Hogwarts, and attempts to persuade him to stay away so he would be safe from harm. When Dobby's attempts fail to persuade Harry, he smashes a pudding in the Dursley family's kitchen. Being caught in the kitchen with the wreckage, and receiving a warning letter for illegal use of magic, Harry is locked up by the Dursleys, who insist that he would not return to Hogwarts, but Ron, Fred and George Weasley are able to rescue Harry in their father's flying Ford Anglia. Dobby later tries to keep Harry away from Hogwarts by magically sealing off the hidden entrance to Platform 9¾, but Harry and Ron foil that plot by piloting the flying car back to school. During a Quidditch match of Gryffindor vs Slytherin, Dobby enchantes a Bludger to chase after only Harry; it manages to break his arm. When Harry – having just returned from the Chamber of Secrets – discovers that Dobby's master was Lucius, Harry tricks Malfoy into setting Dobby free – a feat that secures him the house-elf's undying loyalty.
Dobby reappears in Harry Potter and the Goblet of Fire. He thereafter demands to be paid for his services and he has it difficult to find any employment at all. Nevertheless, he later obtains a post at Hogwarts, and is the only paid house-elf on the staff. In this book, Dobby gives Harry the gillyweed he needs to survive the Second Triwizard Task. Dobby is also the only house-elf who cleaned Gryffindor Tower since Hermione begins trying to set the house-elves free, because the house-elves find the clothes insulting. In Harry Potter and the Order of the Phoenix, Dobby shows Harry the hidden Room of Requirement, which Harry uses for his Dumbledore's Army meetings. When Professor Umbridge finds out about the meetings later, Dobby enters the room to warn the group to leave. In Harry Potter and the Half-Blood Prince Harry entrusts Dobby to help watch Kreacher when he orders him to work in the Hogwarts kitchens with the other house-elves. When Harry needs somebody to follow Draco Malfoy, he is helped by Dobby and Kreacher. When they report back, Kreacher tells Harry only mundane things, such as Malfoy's class schedule, while Dobby cuts to the chase and tells Harry about Malfoy's visits to the Room of Requirement.
Dobby makes his last appearance in Harry Potter and the Deathly Hallows when Aberforth Dumbledore sends Dobby to rescue Harry, Ron, and Hermione from the cellar of Malfoy Manor. Dobby helps Harry and Ron escape their prison and gets Luna Lovegood, Dean Thomas, and Mr Ollivander out of the manor, then helps Harry and Ron free Hermione and Griphook from torture at the hands of Bellatrix Lestrange. While he succeeds in his task, Bellatrix throws a knife at Harry, but the knife hits Dobby instead, who dies before he can be healed. Harry physically digs the grave without using magic, and writes upon the stone: "Here Lies Dobby, A Free Elf".
In Harry Potter and the Chamber of Secrets, Fawkes is summoned by Harry's loyalty to Dumbledore to the aid of the protagonist as the boy fights against Salazar Slytherin's basilisk. Fawkes gouges the basilisk's eyes out, blinding it and eliminating its ability to kill with its gaze. Harry is later wounded by the basilisk's fang; he nearly dies from the venom, but Fawkes heals the wound with his tears, as phoenix tears have healing powers and are the only antidote for basilisk venom. Fawkes then brings Harry, Ron, Ginny, and Gilderoy Lockhart back up to the castle, bearing their combined weight as they hold his tail feathers. During the confrontation between Voldemort and Dumbledore in the Ministry in the climax of Harry Potter and the Order of the Phoenix, Fawkes saves Dumbledore's life by swallowing a Killing Curse from Voldemort. Fawkes then bursts into flame and is reborn as a chick from the ashes. After Dumbledore's death in Harry Potter and the Half-Blood Prince, Fawkes is heard singing a lament for him. When the singing stops, Harry knows that Fawkes has left Hogwarts forever.
Fawkes is named after 17th century terrorist conspirator Guy Fawkes. When asked in an online chat what Bonfire Night was, Rowling replied, "Good question! We celebrate 5 November in Britain every year. There was a plot to blow up the Houses of Parliament. The ringleader of the plot was called Guy Fawkes (spot any Harry Potter connection?!), and we burn him in effigy and set off fireworks to celebrate not losing our government.
The character does not make another appearance until Harry Potter and the Order of the Phoenix, in which he is appointed by Dumbledore to teach Divination at Hogwarts in place of Sybill Trelawney, who had been sacked by Dolores Umbridge. For this, he is cast out of the centaur herd and attacked by his fellows, as Firenze ignored the centaurs' taboo on assisting humans because he felt he had an obligation to contribute to the struggle against Voldemort. In Harry Potter and the Half-Blood Prince he shares teaching duties with a reinstated Trelawney, because Firenze would have no place left to go, as he is an exile from his herd. In Harry Potter and the Deathly Hallows, he is seen near the end of the book fighting alongside the other members of the Hogwarts staff, helping to defend the school against Voldemort and his Death Eaters; it is mentioned that he was wounded on his flanks by the Death Eaters but ultimately survived the Battle of Hogwarts. Although not mentioned in the series, Rowling revealed that Firenze's herd is later forced to acknowledge that Firenze's pro-human leanings are not shameful and allows him back into the fold.
The character is based on Steve Eddy, Rowling's former English teacher who attempted, unsuccessfully, to discourage her from writing mythical, fantasy tales in favour of ones with grittier topics.
He is not seen again until Harry Potter and the Deathly Hallows, imprisoned in the cellar of Malfoy Manor. When Hermione lies under torture to Bellatrix Lestrange that the Sword of Gryffindor is a fake, Bellatrix asks Griphook for confirmation. Though he knows the sword is real, he lies and tells her it is a fake. He is saved, along with Harry, Ron, and Hermione, by Dobby and successfully escaped to Shell Cottage. However, Bellatrix kills Dobby during the escape, and Griphook's respect for Harry grows after watching him digging Dobby's grave by hand without magic. Because Harry needs to get a Horcrux out of Bellatrix's vault, he asks Griphook to assist him breaking into Gringotts. He reluctantly agrees in exchange for the sword of Gryffindor. Griphook and the trio break in successfully but when escaping, Griphook betrays them to the other goblins and escapes with the sword. However, at the end of the book the sword reappears when Neville Longbottom pulls it from the Sorting Hat and slays Nagini.
In the fifth book, Harry Potter and the Order of the Phoenix, Hedwig is intercepted by Dolores Umbridge and is hurt, but is later healed by Professor Grubbly-Plank. At the start of Harry Potter and the Deathly Hallows, Hedwig is killed during Harry's escape from Privet Drive by a stray Killing Curse. According to Rowling, Hedwig's death represented the death of innocence.
Kreacher plays an important part in the book when he betrays Sirius and convinces Harry to go to the Department of Mysteries, where a trap has been laid, to save him. Sirius is killed in the ensuing combat. Following Sirius's death, in Harry Potter and the Half-Blood Prince, Harry inherits all Sirius's possessions, including a highly unwilling Kreacher. Harry immediately orders him to work at Hogwarts, where he comes to blows with Dobby about his lack of loyalty to Harry.
Kreacher also plays an important role in Harry Potter and the Deathly Hallows. When Hermione guesses that one of the Black heirlooms they had tried to get rid of is one of Lord Voldemort's Horcruxes (namely Salazar Slytherin's Locket), Harry and his friends manage to coax the current whereabouts of the locket from the house-elf, and also learn about how Regulus had exchanged the Horcrux at the cost of his own life, and that Kreacher himself was used by Voldemort, who told him to drink the potion out of the basin that would be used to protect the Horcrux. After Harry displays kindness and politeness to Kreacher, the elf undergoes a substantial change in personality, appearing cleaner and happier, and ceasing to mutter insults under his breath. He begins to regard Harry as his new master and fulfils his chores dutifully. Harry then sends Kreacher to retrieve the locket from Mundungus Fletcher; he gives the old elf the fake Horcrux locket as a token of remembrance. In the Battle of Hogwarts, Kreacher rallies the Hogwarts house-elves in the names of Harry and Regulus, and leads them into battle against the Death Eaters. It is implied that he survived the battle, as Harry wonders whether or not he will get him a snack after his battle with Voldemort.
Kreacher appears in the film version of Harry Potter and the Order of the Phoenix, voiced by Timothy Bateson. Producers of the film admitted they had wished to cut an unnamed character, but when Rowling was consulted, she advised: "You know, I wouldn't do that if I were you. Or you can, but if you get to make a seventh film, you'll be tied in knots." Later, director David Yates confirmed that the character in question was Kreacher.
Peeves does not listen to anyone else but Dumbledore, and the ghost of the Slytherin house, the Bloody Baron. Argus Filch, who is usually left with cleaning up the messes and damage Peeves causes, is his nemesis and works continuously to try to get Peeves thrown out; however, Rowling has stated in an interview that not even Dumbledore would be able to rid Hogwarts of Peeves forever. Peeves is, however, vulnerable to some magic; in Harry Potter and the Prisoner of Azkaban, Professor Lupin uses magic to teach Peeves a lesson by making the gum Peeves was stuffing into a keyhole shoot back out and up the poltergeist's nose. In Harry Potter and the Half Blood Prince, Harry also uses magic to glue Peeves's tongue to the roof of his mouth, after which Peeves angrily departs.
Peeves is not completely chaotic nor without loyalties. During Dolores Umbridge's attempts to take control of Hogwarts in Harry Potter and the Order of the Phoenix, his destructive tendencies shift into overdrive and he goes on a rampage. When Umbridge attempts to sneak out of Hogwarts, Peeves chased her out of the castle; alternately whacking her with Minerva McGonagall's cane and a sock full of chalk. Peeves is depicted in Harry Potter and the Deathly Hallows only two times, first where he aids the defenders of Hogwarts by dropping Snargaluff pods on the heads of attacking Death Eaters, and second singing a victory song for Harry at the end.
Rik Mayall was cast as Peeves for film adaptation of Harry Potter and the Philosopher's Stone. However, his scenes were cut from the final film and have yet to be released publicly (being omitted even from the deleted scenes section of the DVD release). Peeves was subsequently omitted from the Potter films that followed, though he can be seen in the Harry Potter Video games. Peeves is, however, referenced in dialogue in the "Queen's Handbag" short film.
In Harry Potter and the Goblet of Fire, she convinces Barty Crouch Sr to let his son attend the Quidditch World Cup; she attends it with the younger Crouch, who is hiding under an Invisibility Cloak, and claims the apparently empty seat beside her is being saved for Crouch Sr. During the festivities, Crouch Jr steals Harry's wand from his pocket and later uses it to conjure the Dark Mark, in spite of Winky's fervent attempts to stop him. In the resulting chaos, Harry and his friends see Winky running into the forest, appearing to struggle against some invisible force. They believe this to be because she is disobeying an order, which house-elves are magically impeded from doing, but actually she is struggling against the invisible Crouch Jr. Later she is caught with Harry's wand, which is magically proven to be the one used to conjure the Dark Mark; though Crouch Sr realises what actually happened, he goes along with the apparent conclusion that Winky conjured the Mark, and frees her, both to save face and as punishment for failing to control Crouch Jr.
Following her dismissal, Dobby takes the distraught Winky to work with him at Hogwarts. There the unhappy Winky, who did not wish to be freed, begins to have a drinking problem that lasts the next several years. Winky eventually sobers up a bit. Rowling has also revealed that Winky remained at Hogwarts and fought in the Battle of Hogwarts with the other house-elves.