GNU/Tux: The spirit of Freedom
The critter is a GNUTux. It has the horns and tail of a GNU, and the kernel of a penguin. The colourful wings just passed by.
In the best GNU tradition, it levitates.
You can get the bakground in PNG format through the screenshots provided. The file attached for download is a TAR.GZ with the SVG source file, which can be edited via Inkscape (http://inkscape.org).