Foiled!
There are countless ways to show a coworker just how much they mean to you and your team. You can get a cake for their birthday or maybe a gift. You could also play a prank on them, which is probably the better, cheaper option. All you need for this prank is a ton of aluminum foil.
Now, take that foil and wrap everything in it—their computer, their keyboard, their office chair, and even any knick-knacks on their desk. Don’t forget the Happy Birthday sign to let them know that this is just a lighthearted birthday prank, only if you want.