Simple dark grey wallpaper incorporating Tux in bottom left corner.
Available in seven different sizes in a tar.gz file:-
1024 x 768 , 1280 x 800
1280 x 1084 , 1366 x 768
1600 x 1200 , 1920 x 1080
1920 x 1200
The Tux icon is also available as a png with an alpha background so
that you can add it to your own colour background/image.
If wallpaper is installed via KDE system settings, the Tux icon and
wallpapers can be found at ~/.local/share/wallpapers.