Whether you use this image for coloring or as a rubber stamp, this black and white large frog drawing just might be what you need. It is in the public domain and ready for downloading. It was drawn by Jessie Wilcox Smith (1863-1935) and included in the 1916 work The Water Babies.
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.