What is the greatest practical joke you have ever pulled?

Mine was work related. I work for a security company. I was igned for awhile to work at an upscale nursing home. One day I was told I would be training the new regional director of the company. I thought ok, if I have to train the guy who is going to be my supervisor I'm going to break him in right. So I got the other officers together and told them one of the elderly residents was suicidal and to just follow my lead. When the new supervisor arrived I called a meeting to brief everyone. I said Old Floyd is talking about suicide again so we have to keep a close eye on him. The supervisor took it all in, looking very serious. The other guards duly noted it in their note books. Well the nursing staff had an anotomically correct dummy that looked just like a real man, hair and eyelashes and all. They had dressed him in pajamas. There was one area of the complex that was a spooky looking old building with a very long hallway with offices on either side, and only dimly lit. So I took the dummy and hanged it by the neck from a pipe with a piece of rope and turned a chair over to make it look like he had kicked it over. Then I took the new guy on rounds and had some of the other guys go along too. When we got to the hallway I told the new guy to go on down and check the doors on the right and see if any are unlocked and if so to check them out. We hung back and watched him. When he came to the office he opened the door and in the dim light all he saw was the overturned chair and the legs of the dummy hanging there. Then his eyes travelled up the "body" and said "Oh my God." I'm doing my best to keep a straight face. I ran up beside him, looked in, said Oh crap, and then quickly closed the door. And I said to him leave it for the next shift to find, there's too much paper work to do with a suicide. Now the other guys couldn't hold it anymore and they all cracked up and then I lost it too. The new guy screamed are you guys crazy! And took off running down the hall. When I finally caught up with him I told him the truth and took him back down to the office. Apparently he went back to the corporate office and told H. R. you have an officer down in West lake who is crazy. When H. R. called and asked me what happened I said what ever do you mean? She said the new guy just quit. They've never had me train new supervisors since. I can't understand why.