I’m the annoying guy in your office that likes to pull little pranks on other people in the cubicle farm. I go for small scale stuff though, lower your chair, unplug your keyboard, draw something on your notepad 20 pages in. One of my favorite harmless ones was when I took a photo of a coworker’s desk and then made that her desktop image. I then took another photo (with the computer right in the center) and made that her desktop image. I repeated it another bunch of times until the recursive image was small enough to resemble reaching into infinity.