About the Illustrator:
Roger Peet is an artist, printmaker, muralist etc. etc. living in Portland, Oregon. He coordinates the national Endangered Species Mural Project, and helps to run the cooperative Flight 64 print studio in Portland. Check out his other work HERE(https://www.bonfire.com/store/toosphexy/).
Reverse image search gives out this: someone by the name of toosphexy on instagram
According to the post they were commissioned by a book publisher for a t-shirt.
heres the link: https://pmpress.org/index.php?l=product_detail&p=1219
and this was written in the description: