We did a quick prank on our brother by using a Raspberry Pi Pico to ghostly type 'you have been hacked' into his computer. We used CircuitPython for this little project.
Plug the pico into a computer and it will act like a USB keyboard and type a message. We added a start button to set the prank in motion after a certain delay which you can set in the code. It will repeat the ghostly message untill you press the stop button.