Professor Trelawney

The following fictional characters are staff members and denizens of Hogwarts in the Harry Potter books written by J. K. Rowling.

The following are notable teachers and staff members who do not have their own articles or who are not listed in other articles.

Argus Filch is the caretaker of Hogwarts. While he is not an evil character, he is ill-tempered, which makes him unpopular with the student body, and occasionally with other staff. His knowledge of the secrets and short-cuts of the castle is almost unparalleled, except perhaps by the Weasley twins, Voldemort himself, Harry, Ron and Hermione, and other users of the Marauder's Map. He tends to favour almost sadistically harsh punishments, leading to his alliance with Umbridge. He has an obsessive dislike of mud, animate toys, and all other things that might interfere with his creation of an immaculately clean and orderly Hogwarts. He is also portrayed as having a constant antagonism towards Peeves the poltergeist and often tells Dumbledore that Peeves should be thrown out of Hogwarts. He also likes to wander Hogwarts corridors at night, presumably in the hope of catching a student out of bed.

Filch is revealed to be a Squib in Harry Potter and the Chamber of Secrets when Harry accidentally discovers that he is trying to teach himself basic magic from a Kwikspell correspondence course. Nonetheless, Filch is at least able to use wizarding devices that have their own innate magic, such as the Secrecy Sensor used in Harry Potter and the Half-Blood Prince. It is hinted that his dislike of students may stem from his disappointment and jealousy at not being able to do magic. In the Half Blood Prince, Harry and Hermione jokingly suspect that he is in a relationship with Irma Pince, the librarian at Hogwarts. In Harry Potter and the Deathly Hallows, the final book, when the school starts preparing itself for the Battle of Hogwarts, Filch is seen yelling that students are out of bed. He is later seen overseeing the evacuation of younger students.

...
Wikipedia