Disclaimer: Don't own HP, happy?
10 Ways to Annoy Filch
1) Sell Mrs. Norris to a Chinese restaurant (BTW: I am Chinese – so I am not making fun of Chinese people, but in my opinion, a lot of these restaurants are crap)
2) Plaster frog brains all over his office.
3) Dress up as Peeves.
4) Get the Kwikspell owners to come to his office.
5) Ask him complicated magic questions
6) Carve "Madam Pince + Filch 4ever" on his door.
7) Hang him up by his own chains on the roof of his office.
8) Lock the Bludgers in his office – see how much damage they'll do.
9) Lock Mrs. Norris in a filing cabinet.
10). Pour glue into the keyholes of the building.
A/N: the last prank is based on one that some idiot senior did at my school. Apparently, he was fined about ten thousand dollars for it – all the locks had to be replaced.