"Well, well, well, we are in trouble."
-- Argus Filch (PS14)
Argus Filch is the notoriously cranky caretaker of Hogwarts, famous for his bad temper.
Filch is the Hogwarts caretaker. He’s a cantankerous, nasty man who detests the students. Filch has a “scrawny, dust-colored” pet cat called Mrs. Norris with whom he has an almost psychic connection. She wanders the corridors of the castle just as he does, and if she spots anyone putting a toe out of line, Filch is there within minutes. He knows the secret passageways and hidden doors of Hogwarts better than anyone except Fred and George Weasley (and now Harry, thanks to the Marauders’ Map).
Filch is a Squib, which means that he was born of a wizarding family but cannot do magic. The frustration this causes is partly to blame for his horrible and vindictive attitude. Hanging from the ceiling of his office are chains and manacles which he keeps polished up in case he’s ever given permission to use them on students, something he would dearly love. Under Umbridge, Filch actually walked the halls of Hogwarts with a horsewhip (OP29). During the Battle of Hogwarts, Filch helped Madam Pomfrey evacuate the students from the school (DH31). There is no record that he stayed to fight.
Hogwarts: Hogwarts Caretaker; his office is probably on the ground floor (…more information on Filch’s office).
Appearance: Rheumatic (OP28) and hunchbacked, Filch wheezes and shuffles when he walks (PS). He has pale eyes, jowls that quiver (PA8), and thin grey hair (OP14). He wears a brown coat (PA11).
Interests: Kwikspell courses (CS8), torturing students for infractions, giving detentions, and polishing the manacles hanging in his office.
Cleaning, enforcing rules, being Umbridge's lapdog.
Argus = giant in Greek mythology, a watchman with a hundred sets of eyes (200 in total).
Filch = English slang "to steal."