Originally posted by: DrPizza
A lab I used to work in was known for practical jokes. You *HAD* to be on your toes at all times, otherwise you were a victim.
It may be hard for you to construct, but a water-catapult, finely tuned hidden under the desk can result in a very wet crotch area. Just takes a few pieces of wood, some giant rubber bands, and a cup of some sort nailed to the catapult. Practice with varying amounts of water; eventually you'll find the right volume to fill the cup with and right distance from the chair to result in an embarrassing wet spot.
Match tips from wooden matches... get a bunch of them into a pile and carefully put them under a table or chair leg. It's like a miniature pipe bomb if done correctly; about as loud as a fire cracker.
Firecrackers in the drawers. Opening the drawer causes one to be lit. (wooden matches, tape, firecracker, and sandpaper needed here)
What kind of phone? There are all sorts of jokes that can be done with phone cords. Simplest ones include using fishline to connect beginning of cord to the end of cord... answering phone results in ripping the phone cord out. Also, fishline from receiver to some out of view object can result in amusement for others.
If his chair is on rollers, remove one of the rollers. The wobblyness of the chair will annoy him all day.
Make a mousetrap trebuchet (catapult) which is triggered when his drawer opens. Very inexpensive to do, but takes a LOT of engineering to perfect it. (but, the best practical jokes take planning) Just find something appropriate to fling at him.
Too late to observe him, but since the mousetraps come in 3 packs...
Someplace, he's bound to open something by grabbing underneath it. Or, engineer something for him to have to open the hard way... if he has a center drawer below the desktop, simply remove the handle. He'll be forced to reach underneath to grab it to open it. It doesn't take a rocket scientist to figure out where to duct tape a few mousetraps. 🙂
*for what it's worth, I just thought of the last 3. If you should attempt any of them, please let me know how they worked 🙂