This charming little Oriental frog was included in a larger drawing. The book I found it in was from 1765. It is the work of Katsuma Ryûsui.
The brown and green frog has a certain charm about him. Don’t you think?
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.