A rooster crows cock-a-doodle-do while standing upon a fancy letter C. This drop cap letter C image is in the public domain and ready to be downloaded.
I found several similar fancy letters images, drawn by Gordon Browne (1858-1932) in National Rhymes of the Nursery.
This image is copyright free and in the public domain anywhere that extends copyrights 70 years after death or at least 120 years after publication when the original illustrator is unknown.