Lupin teaches his students in Defence Against the Dark Arts to approach a boggart in groups of two or more, or even to think of several very different frightful beings (Professor Snape and grandmother Augusta, in the case of Neville) so that the boggart will have difficulty in choosing how to frighten whom. The Riddikulus charm is used to combat Boggarts, by changing their appearance into a less fearsome or even comical apparition, which weakens the creatures. When Harry Potter approaches the boggart, it takes the form of a Dementor. Albus Dumbledore gives the same lesson in Fantastic Beasts: The Crimes of Grindelwald. Centaurs Centaurs in the Harry Potter universe are wild creatures who claim to possess intelligence greater than humans. Their heads and torsos resemble those of humans but they possess the four legs, lower bodies and tail of a horse. Although sentient, they have not requested assignment as beings, preferring to remove themselves entirely from human affairs. Centaurs who decide to associate with humans can be seen as traitors to their kind and attacked by other centaurs, as was the case with Firenze, who agreed to teach Divination at Hogwarts. Firenze's interest and involvement with human affairs resulted in violent reprisals by other centaurs and were it not for Hagrid's intervention, Firenze could have been killed. The Ministry of Magic's Department for the Regulation and Control of Magical Creatures has a Centaur Liaison Office, but no centaur has ever used it. Centaurs are skilled in healing and astrology, and spend much of their time scouring the stars for portents. They live in forests, and their society consists of groups called herds. They do not appear to employ or need any technology more advanced than a bow and arrow. They are proud and territorial, therefore high diplomatic skills must be employed when dealing with centaurs. Displaying lack of respect to centaurs can have violent consequences, as Dolores Umbridge learned to her cost. In Deathly Hallows, the Hogwarts centaur herd, after being admonished fiercely by Hagrid, takes sides with the Order of the Phoenix, and assist in the Battle of Hogwarts. The films depict the centaurs with bestial and animalistic facial features. The books do not describe them, but several female students are attracted to them. Named Centaur characters: Firenze Bane Magorian Ronan Dementors The dementors are "soulless creatures... among the foulest beings on Earth": a phantom species who, as