There used to be something of a game of making specific files that would change screen colors or play songs off terminal bells, etc, tailored for specific terminals or command prompt windows. I remember a few short animated sequences using various backspaces and colors that only really worked if you could expect the text to be loaded at specific baud rates or in specific BBS software.

Many years ago someone "infected" my computer with a "manual virus": A printed-out sheet of paper placed on top of the computer, telling me to delete all my hard drive's files myself, then photocopy the sheet and put both copies on nearby computers.

It was obviously a joke. But in the "modern" agentic era, the same thing in a text file is slightly more realistic as a threat...