Hogwarts, being a school, is often filled with many humans — but have you ever stopped to think what else lurks in the corners of Hogwarts? What or who that cat was that passed you in the Library? What hides deep within the Forbidden Forest? Let us enlighten you!
House Elves House Elves are the only creatures that live in the Hogwarts castle. They are the property of the school. They can often be seen working in the kitchens, doing chores such as cleaning, making beds and keeping the school in tip top form. These little creatures are the ones who bake, cook and serve the school meals. Contrary to popular belief, the Hogwarts Elves are treated kindly, under rule of the Caretaker.
The merpeople of Hogwarts have greyish skin and long, wild, dark green tentacles. Their eyes are yellow, as are their broken teeth, and they wear thick ropes of pebbles around their necks as necklaces. Their powerful, silver fish tails allow them to swim expertly, while the upper parts of their bodies resemble those of humans. Merpeople are also very tall, and during the second task, Harry encountered one in the lake near Hogwarts who was seven feet tall with a long green beard and a choker of shark fangs, carrying a spear. They have been known to keep Grindylows as pets, and use Lobalugs as weapons. One tribe even managed to capture and domesticate a Hippocampus.
Hogwarts has its own Owlery. It makes sense, considering most students and faculty own an owl. These birds are used around Hogwarts to deliver messages, collect mail and be a companion to the witch or wizard that chose them. Each owl is different and like cats, come in an array of colors and personalities. Some may peck you and some may love you.
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 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.
Ghosts play an important secondary role, mainly as advisors. Unlike the ghosts in a traditional ghost story, these ghosts are neither frightening nor necessarily ghoulish, and many ghosts act as advisors to live humans in their times of need. Ghosts in the novels appear silvery and translucent. They can fly and pass through walls, tables and other solid objects, but nonetheless have some ability to physically affect, and be affected by, the living world. Moaning Myrtle can, for instance, splash the water in her toilet. Ghosts’ banquet tables are laden with rotten food, as the decomposition increases their ability to almost smell and taste it. Touching or walking through a ghost induces a sensation “like walking through an icy shower.” Ghosts can be affected by magic and curses, though not to the same degree that living beings can, and they can, obviously, not be killed by them as they’re already dead.
In the Harry Potter universe, only wizards and witches 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.