See Moof. The dogcow is a semi-legendary creature that lurks in the depths of the Macintosh Technical Notes Hypercard stack V3.1. The full story of the dogcow is told in technical note #31 (the particular dogcow illustrated is properly named ‘Clarus’). Option-shift-click will cause it to emit a characteristic “Moof!” or “!fooM” sound. Getting to tech note 31 is the hard part; to discover how to do that, one must needs examine the stack script with a hackerly eye. Clue: rot13 is involved. A dogcow also appears if you choose ‘Page Setup...’ with a LaserWriter selected and click on the ‘Options’ button. It also lurks in other Mac printer drivers, notably those for the now-discontinued Style Writers. See http://developer.apple.com/products/techsupport/dogcow/tn31.html.