The other day I was invited via the LFG queue to join in on a heroic Mechanar run. The other four players were all in the same guild and seemed to be good friends, based upon the way they were joking around while we all made our way to the instance. Not long after we entered the dungeon, I received private messages from three of the other group members telling me that they were going to play a practical joke on the tank. As soon as he attacked the first creature, the rest of us were going to run out of the instance, leaving him alone to die. I wasn't really sure what to make of the idea, but when they all ran out, I followed, not wanting to die myself. The guy seemed to take it well and laughed it off with some good natured teasing, but I've seen similar situations where the outcome wasn't as pleasant.
For instance, several months ago, when my guild was trying to enlist new members to raid the larger dungeons, we were in an alliance with another guild for a short period. A lot of the people in my guild like to joke around and one of them decided to play a prank on the hunters in the raid while we were learning how to take down Gruul. After the tanks died on one of our attempts, this player decided it would be funny to run to the area near the doorway where the hunters were feigning death, hoping to avoid repair bills. Of course, he pulled Gruul right on top of the hunters, turning their fake deaths into real ones. Most of them laughed it off, but one guy in particular became really upset and made a big commotion in raid chat. It took him awhile to calm down, but the group eventually pulled it together and went on to kill Gruul.
Ever had an experience like this? Does this sort of thing annoy you or do you think it has a place in WoW?