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Post-it car - Your coworker will be in for a huge (and hysterical) surprise when they see their car covered in post-it notes. (Photo: CC BY 2.0)

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Sticker keyboard - Cover your coworker's keyboard in stickers. Bonus: find stickers with images of something they absolutely can't stand. (Photo: CC BY 2.0)

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Tin foil cubicle - If you have a lot of time, this one is definitely worth it. Hopefully your coworker has a sense of humor, as they will have to unwrap every little piece of foil. (Photo: CC BY 2.0)

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Banded phone - Hopefully your coworker won't be expecting any important calls right when they arrive in the morning! (Photo: CC BY 2.0)

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Jell-O stapler - We can thank Jim from 'The Office' for this classic prank. Take any of your coworker's office supplies and mold it in Jell-O. (Photo: CC BY 2.0)

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Christmas came early - No tin foil? No problem! Use wrapping paper to cover everything in your coworker's cubicle. (Photo: CC BY 2.0)

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Balloon mania - Your coworker will have to wade through a cubicle stuffed with balloons. (Photo: CC BY 2.0)

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Fish tank drawer - Turn a file cabinet into a fish tank by removing the files, filling it with water, adding fish, and then covering the top with plastic wrap. Make sure you have a camera ready when your coworker opens the drawer!

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Did you hear that? - Hide a tiny speaker on your desk and play the sound of a cat meowing every couple of hours. Then listen and enjoy as your coworkers try to figure out where the sound came from.

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Granny panties - Write a coworker's name in a pair of old granny panties and leave them on the floor of the bathroom. This one is super embarrassing—but hilarious!

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They're watching you - Stick googly eyes to your coworker's desk supplies.

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Yearbook photo - If you have access to it, take a coworker's 8th grade yearbook photo, blow it up, make copies, and plaster it to every surface of their cubicle or desk.

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Toilet chair - Replace a desk chair with a toilet for that one coworker who always seems to have way too much to do and no time to get it all done.

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Clean hands - Replace hand sanitizer with lubricant and watch as your coworkers try to figure out why the gel is so slippery.

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Minty fresh - Replace the cream inside Oreos with mint toothpaste and then generously offer them to your coworkers.

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Car freshener - Tape a bunch of car fresheners under your coworker's desk and chair. They won't be able to figure out why they keep getting whiffs of pine trees.

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Copier fun - Make photo copies of your own face and decorate your coworkers' cubicles and desks with them. Another idea is to place the images of your face in random places throughout the office and see how long it takes your coworkers to find them all.

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Glitter bomb - The glitter bomb is an oldie but a goodie. Fill an envelope with glitter and watch your coworker open it and release the glitter all over themselves and their area.

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Cake prank - Bake a cake for the office but add a twist. After frosting it, write "find the toenail" on top. See which one of your coworkers actually dares to take a piece of the cake.

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Desktop background - Take a screenshot of your coworker's desktop background. Then, move all of their folders into one and replace the background image with the photo you took. See how long it takes them to call over an IT guy to explain why they can't open the folders on the desktop no matter how many times they click on them.

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Voice activated appliances - Bring in a new toaster and face the control knob to the wall. On the opposite side, attach a sign reading "voice activated." Watch your coworkers shout at the toaster to no avail.

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Haribo gummy bears - If you're feeling especially cruel, place a bowl of Haribo sugar free gummy bears in the break room. Your coworkers will be fighting over access to the bathroom.

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Unexpected playlist - If your coworker leaves their Spotify open on their computer, sneak in while they're away from their desk and add random and ridiculous songs to their playlists.

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Creepy crawlers - Take a mug and turn it upside down on your co-worker's desk. Attach a note to it reading, "don't move this cup unless you're planning to kill it."

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Broken mouse - Place a sticky note underneath your coworker's mouse and watch their frustration build as they can't get the cursor to do what they want.

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Not-so-sweet breakfast - Bring in a donut box filled with vegetables. Your coworkers will be sure to hate you for it, while you can just laugh at their disappointed reactions.

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Cover your ears - Tape an air horn underneath your coworker's office chair so that when they sit down, they will trigger the horn.

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False notes - Throughout the day, continuously leave notes hinting at an April Fool's prank that doesn't actually exist. Your coworkers will be on edge all day in anticipation and fear.

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Fake firing - Place the contents of a coworker's desk in a box and leave it on the floor. When they walk in, feign surprise and say, "what are you doing here? I thought you got fired."

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