Mr Filch
Background
Argus Filch is the caretaker at Hogwarts School of Witchcraft and Wizardry. He has a pet cat named Mrs Norris. He is enrolled at Kwikspell and is taking a correspondence course in beginner's magic.
During the events of Harry Potter and the Sorcerer's Stone (2001) played by David Bradley
Harry Potter uses his Invisibility Cloak to go into the restricted area of the library and is almost caught by Mr Filch. Mr Filch shows Professor Snape and Professor Quirrell the lantern he found in the restricted section. Later, for detention Harry, Hermione Granger, Ron Weasley and Draco Malfoy are brought by Mr Filch to help Hagrid in the Dark Forest.
During the events of Harry Potter and the Chamber of Secrets (2002) played by David Bradley
Mr Filch], who is holding Mrs Norris, stops Harry and Ron and tells them that might be there last night in the castle and tells them they are in trouble. Later, Ron, Harry and Hermione find Mrs Norris hanging in the air and a crowd gathers around and Mr Filch threatens to kill Harry when he thinks it was him that hurt Mrs Norris. Albus Dumbledore and the professors walk up and Dumbledore tells the students except for Harry, Ron and Hermione to return to their rooms. Professor Snape says it is suspicious how Harry was present at the time and Gilderoy Lockhart tells him, Harry was with him. Dumbledore then mentions Professor Sprout's Mandrakes and tells Mr Filch, Mrs Norris will be fine. Later, Mr Filch sees Harry standing over the body of Justin Finch-Fletchley and leaves to tell others. Professor McGonagall tells Professor Snape, Madam Pomfrey, Professor Flitwick, and Mr Filch, Ginny Weasley was taken to the Chamber of Secrets and all the students must be sent home. By the end of the school year, those who were petrified recover.
During the events of Harry Potter and the Prisoner of Azkaban (2004) played by David Bradley
The students take a trip to Hogsmeade Village and Mr Filch takes their signed passes from their parents. Later, the Fat Lady in Painting disappears from the common room portrait. Dumbledore arrives with Mr Filch, who is holding Mrs Norris, and Dumbledore tells Mr Filch to round up the ghosts to search for the Fat Lady. Mr Filch spots the Fat Lady and she tells them Sirius Black is in the castle.
During the events of Harry Potter and the Goblet of Fire (2005) played by David Bradley
As Dumbledore is talking to the students, Filch runs up and tells him something. Dumbledore continues and tells the students that Hogwarts will be hosting the Triwizard Tournament. Dumbledore introduces Madame Olympe Maxime and the students of the Beauxbatons Academy of Magic, including Fleur Delacour. He then introduces Igor Karkaroff and the students of Durmstrang, which includes Viktor Krum. The Goblet of Fire is brought into the hall and Dumbledore tells the students that whoever wins the tournament will have eternal glory. Alastor "Mad-Eye" Moody walks into the hall and is greeted by Dumbledore. Barty Crouch tells the students that no student under the age of 17 will be able to apply to participate for the Triwizard Tournament. As McGonagall is explaining the Yule Ball to the Gryffindors, Filch turns on the record player before she has Ron dance with her.
During the events of Harry Potter and the Order of the Phoenix (2007) played by David Bradley
During the Hogwarts banquet, Dumbledore welcomes back Professor Grubbly-Plank as the Care of Magical Creatures while Hagrid is away. He then introduces Dolores Umbridge as the new Defense Against the Dark Arts teacher. Dolores interrupts Dumbledore and tells the students that the Ministry of Magic is very concerned about their education. Later, Filch posts a decree stating that Dolores has been appointed as the Hogwarts High Inquisitor. Professor Sybil Trelawney is fired by Dolores and Dolores has Filch bring Trelawney's things out to the courtyard. Dumbledore walks out into the courtyard and has McGonagall bring Trelawney's things back inside and tells Dolores she can only fire professors, not expel them from Hogwarts. Dolores sees Harry and the others walking back to Hogwarts and makes a decree that all student organizations are banned. As some of the students train in practical magic, Filch tries to discover their hideout. After Finch continues to fail at finding their secret hideout, a student Inquisitorial Squad is created and Draco, Crabbe and Goyle join it. During one of Dumbledore's Army's training sessions, they are caught by Dolores, Filch and the student members of the inquisitors.
During the events of Harry Potter and the Half-Blood Prince (2009) played by David Bradley
Luna Lovegood and Harry see Mr Filch inspecting Draco's belongings before Snape intervenes. Later, Draco is caught near Professor Horace Slughorn Christmas party by Mr Filch and brought before Slughorn who is with Eldred Worple and Snape drags him outside.