A gnu in the savannah speaking "Gnus come in a herd. Learn which Free software has been used to create this application and which is recommended with it's use". Text can be easily adjusted. usegroup sponsored creative commons artwork by Stephan Baumann.
This is a completely free image Gnu speaking that you can download, post, and use for any purpose.
Image License: CC0 No Rights Reserved
You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission, and at no cost. This image is completely free.