No More Ink
Remove the ink from inside the pens and put them all back in the box.

Problem With Chair Wheels
Use some black tape to tape up the bottom wheels of your victim's desk chair. This will make it difficult to move the chair. Most people will never take the time to look and fix the problem and will just leave it at a nusance.

Sinking Chair Prank
Most office chairs nowadays have a pneumatic piston used to control the height. The chairs are also designed to use a person's weight to control the downward adjustment. So, while your victim is away from his chair, tape the height adjusting lever to the bottom of the seat. This will make the piston lock and when your co-worker takes a seat, he will end up sinking all the way to the bottom.

Salt Cookies
Bake a few batches of sugar cookies to take to the office every now and then so they all get used to your wonderful delicious cookies. Then one day just replace the sugar ingredient with salt. If anyone asks, tell them you are trying to cut down on the sugar intake and make them healthier.

FBI Answering Machine Prank
Change someone's answering machine so it says, "This is the FBI. All calls being made to this phone number are being traced and logged." Don't tell him, find out how long it takes him to realize it.

Unable To Open Desk Drawer
Go underneath and behind desk drawer to tape it up so it cannot open all the way. This will frustrate your victim who needs to go in the drawer just to grab a pen or a notebook.

Memo: Free Pizza in the Lunchroom
Send out an email memo to everyone in the office to let them know about FREE pizza in the lunchroom. Then sit back and wait until the line of co-workers fills the hallway on their way for pizza that isn't even there.

Rear Injection
If you work at a place where shots are either required or encouraged, chances are your company has a day where physicals are free and everyone takes turns getting a shot when the doctor shows up on a certain day. Well, for this prank, before going in to get your shot on the upper arm...make sure you in line in front of the new guy. Then proceed to undo your pants, walk in, get your shot and come out zipping back up and rubbing your bum. The new guy will think the shot is actually in the rear and will be a bit freightened.

Office Raffle
Put an envelope in your victim's mail box slot. In the envelope put a letter with a return envelope. The letter will say something like "Office Raffle - $1 each ticket". Then make up some fake prizes like a new new car grand prize, new computer seconds prize and 5 runner up cash prizes, etc. Have your victim put his dollars in his envelope and put back in mailbox. Then later, go get this envelope of money and put some fake raffle tickets in his box.

Looking For A Stripper?
Place an ad in the newspaper or on any classified website. In the ad, say you are a stripper and can strip at parties for half the price and double the time than a regular stripper. Leave the secretary's name and your company number as the contact info.