I had several random students walk into class today and start distracting kids while they were working. This actually happens all the time in this district; often enough that I assume it must be "normal." Each time I would just boot them out.
So, when someone quietly walked in (the kids all have their backs to the door) dressed in a Halloween horror mask, and long cape, I didn't care that he was putting his finger to his lips, motioning for quiet. I just said, "alright, take the mask off and get out of here."
It turned out that it was a teacher, hoping to get a scare from the class. He muttered something along the lines of, "at least I got the other class" as he hurried back out the door.
I felt like a total jerk, but given the day I had had, I don't think my reaction was unjustified.
The following happened in an Honors Geometry class.
While moving around the room helping kids classify angles, I noticed two of the geekier students in the back throwing papers balls at each other.
I moved back to their desks and said, in my sternest "teacher's voice," "Hey. What do you think you're doing?"
A girl looked up at me, obviously embarrassed, and possibly slightly intimidated and replied, "we were LARPing... I just cast Magic Missile on him."
After that, all I could do was turn and walk away.
I have to admit, in almost 5 years of subbing, I have NEVER heard that one before.