Make Roll-Out Cookie Dough, or use refrigerated cookie dough. Roll out 1/8 in. thick; cut "S" cookies. Bake 7-9 minutes or until edges begin to brown; let set on cookie sheet 1 minute. Remove from sheet and cool completely.
Place cookies on cooling grid over parchment-lined pan. Tint dark and light versions of thinned royal icing desired snake colors, using icing colors. Cover cookies with thinned darker colored icing, allowing icing to flow over edges of cookie; immediately add lines and dots with lighter tinted icing. Let dry. Add tip #7 white royal icing dot eyes and Tip #2 black dot pupils and nostrils.