You can put them onto your Plasma wallpaper and/or lockscreen background with plasma-wallpaper-application: https://invent.kde.org/dos/plasma-wallpaper-application
(thought I'd share that since its raison d'être was to put Asciiquarium there :))
Plasma wallpaper plugins are, well, for Plasma.
When it comes to wallpapers, you could do a similar trick on X11 DEs by putting it onto the root window (with a tool like xwinwrap) and on Wayland DEs that support layer-shell (with a tool like windowtolayer). I'm not aware of screen lockers that do something like that, but you could always write your own one.
Nice. This makes them actual screensavers in my view as opposed to just animations. (Not that screens require "saving" any more, but still.)