I have a "boss" who I've been working with for about 5 years. We have always been playing little jokes on each other back and forth...
An example of one of the smaller jokes I played on him:
He's an avid Yankee fan. It was during the Subway Series... I had a custodian let me into his office, which I proceeded to decorate with Mets colors in balloons, streamers, and post-it notes. When he walked into his office the next morning, he didn't even know what to say.
The one joke I wish I could have gotten over on him had been cut short due to scheduling errors. Before he was promoted to VP in another building, he was the Student Activities Coordinator (when I was a class advisor - so he's always been my "boss"). He had to schedule all sorts of different activities for this "activity period" they were adding into the students' schedules. The kids got to pick different activities (sewing, board games, math club, chess club, etc.) to keep them occupied every other week. Some of the kids wanted a breakdancing club. So, he started to check into it with insurance, liability, etc.
Knowing he was under the gun timewise, I did some of the research for him. I gave him the web address of a company that specialized in teaching breakdancing. They would come and give the first lesson free, and then work out a deal with school districts. Unfortunately, the Superintendent of Schools said that everything was taking too long and cut the program out. So, no board game club, no sewing club, and no breakdancing club.
Where was the practical joke in all of this? The group didn't exist. I designed the webpage, found space for it, and put it up. The phone number for the group was a She-Male Escort service. This would have been the best practical joke ever, but unfortunately, it didn't come to fruition.
I'm working on the next one. I will get him
muahahahaha.