Package xpenguins

https://ratrabbit.nl/ratrabbit/software/xpenguins/

XPenguins animates a friendly family of penguins in your root window.
They drop in from the top of the screen, walk along the tops of your
windows, up the side of your windows, levitate, skateboard, and do
other similarly exciting things.  XPenguins is now themeable so if
you are bored of penguins, try something else.  The themes that come
with this package are "Penguins", "Classic Penguins", "Big Penguins",
"Turtles" and "Bill".

The penguins are able to walk on X11 windows, but are ignorant of
Wayland windows. Some of the effect is lost by this.

Version: 3.2.4