In college we had a Linux computer lab just for CS majors. At the time we had an HP printer that allowed for updating the screen text with a network command.

The computers were never really shut down, so you could just lock it when away. I wrote a script that cycled through various messages like “PC Load Letter” and “Skynet activated, stand by for terminator” with a countdown from 10 to “Terminator Deployed”.

It really confused the lab techs that would help people with printer issues.