Created from a public domain photograph originally made by Master Sergeant Jose Lopez, Jr. of the United States Air Force:
http://commons.wikimedia.org/wiki/Image:Emperor_penguin_chicks_at_Sea_World_%C2%B7_DF-ST-90-04598.JPG
Created using Paint.NET (http://www.getpaint.net/) and Potrace (http://potrace.sourceforge.net/).