@drq Somewhat related pranks we did sometime:

1. If you are mail admin (or can create recipients) make an account mimicking someone important (maybe not CEO unless you want your ass fired but your boss or their boss will do) replacing one letter from another layout or just using similar ones (I and l being usual favorites). Hide it from the address book and initiate some correspondence involving that account and some pranksters about something sensitive involving your victim. Then "accidentally" leak it. The victim won't go to the boss (hopefully) because they are not supposed to see it but they'll get all squirmy and start asking around about salary cuts or whatever.

Or they will go to the boss or the boss above that boss and then the prank is on you :)

2. Make a computer account mimicking your victim in the same way. When they leave the room, log with that very similar account and lock it up. Watch them trying to enter password. Help them reset it multiple times because you don't know why it doesn't work, is your keyboard ok? Let's test it on my PC, look, you can log in just fine, go and type your new password, it must work. Look, it works on your phone. Maybe try to reset your password yourself from my PC? Oh, bummer.... No, I didn't do anything, let's reboot your computer, must be Windows glitch.