The diagram
So, as a teacher, giving punishments is part and parcel of my daily grind. I don't particularly enjoy telling-off as a rule, but when it needs to be done, I do try to find some way to add amusement value, particularly when the crime deserves some special attention.

My favourite, and one of my own devising, is the punishment for a naughty boy who decided to draw a giant man-sausage on his exercise book. He wasn't a bad lad, but could step out of line rather far on occasion, and so I couldn't let it slide. I kept him behind at the end of the lesson, and his lecture went as follows.

"This is an absolutely pathetic diagram, one of the worst I have seen you produce. (*pause for blank look). You are going to finish it, at home, tonight. (Pause for more confusion.) It is going to be correctly, accurately labelled. No mistakes. No mis-spellings. No crossings-out. This diagram is going to be perfect. Do you understand? Now get out of my classroom."

He leaves, rather puzzled, and the next day, returns with a magnificently labelled version. It is accurate, detailed, and he has done more work on it than any other homework that year so far. In front of him, I tore it out of his book, placed it in an envelope and put it in my desk drawer.

"Now, the next time you muck around in my lesson, what do you think I will bring to the meeting I have with your Mum?... Clear?"

This brought, in fairly quick succession, 1) more puzzlement. 2) a moment of brief panic, and 3) a polite nod and a mumbled "sir".

He was pretty well behaved after that...
(Serotonicity was a naughty boy on..., Wed 13 Feb 2013, 17:32, 6 replies)

Hahahaha
This is ace. When I was in the upper sixth and a prefect, I was able to dole out punishments to younger boys at the school, traditionally two sides of lines copying out the school motto over and over again, but I preferred to make them write a two-side essay on the subject of my choice. I probably still have some of the more amusing ones somewhere, must look them out sometime.
( emvee cruor deo cruoris, Wed 13 Feb 2013, 18:02, closed)

was
It you that posted a similar tale a while back?
(Suck it and Sea, Wed 13 Feb 2013, 18:13, closed)

Bugger. Yes. Forgot I had already told the tale.
(Serotonicity was a naughty boy on..., Wed 13 Feb 2013, 18:18, closed)

Marvellous
*clicks
( social hand grenade I was a lurker before you were a lurker, Wed 13 Feb 2013, 19:42, closed)

"Mum,
my teacher keeps an anatomically accurate rendering of my penis, in his desk."
( monster munch person, man, woman... camera... TV?, Wed 13 Feb 2013, 19:44, closed)

Subsequent investigation by the head uncovers the drawing in question.
The paper is strangely sweat-stained and crinkled.
( drimble he'd been white, he'd been black, Wed 13 Feb 2013, 20:38, closed)