This drop cap letter O image looks a bit like an art deco piece. A central letter O is surrounded by gentle doodles that look like smoke. This letter image is in the public domain and can be freely used in your projects.
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.