I love old UNIX tools and techniques, but I want to run current software to take advantage of what it has to offer. I still customize my .xsessionrc to initialize my environmentI on startup and run stuff like gkrellm and xscreensaver. The more time that goes by the harder this sort of thing seems to be to do as stuff like systemd and gnome swallow the world. The struggle is real.
One fun little thing I do on my workstation at work is on weekday mornings, I have a cronjob run that uses xcowsay to display an offensive fortune. It's a nice way to start the day. I sit down, wiggle my mouse, and right on top of my lock screen is a cow telling me a random quote that is generally incredibly offensive. I like to think it helps me to not take things too seriously. Sometimes I laugh. Others make me cringe. Sometimes I click it away as fast as I can. Usually I at least smile though.
If you work with me and you are in my office first thing in the morning for some odd reason before I get there, you have been warned. Leave my system alone unless you are alright with this sort of thing. It's on you.
Anyways, to do it yourself, install the packages for xcowsay, fortune-mod, fortunes, and fortunes-off (at least that's what they are on Debian). Then edit your crontab and put something like this in place:
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games 0 6 * * MON-FRI export DISPLAY=:0 && fortune -o | xcowsay -t0
At least with xscreensaver, this plops right on top of the screenlocker. I'm not sure if it appears above any currently running hacks or not, but since my display is always asleep at 6am I'll probably never know (or care).