This nifty tattoo comes from the Flickrstream of cp_odd and is licensed under Creative Commons. No artist information provided.
This tattoo is based on original art that I've seen elsewhere on the web at least a hundred times. But, of course, now that I'm want it for the sake of comparison I can't find it. At any rate, a very nice Green Man to bless your day.
Update: Fabulous reader Niklaus has informed me that this Green Man is from the wonderful fantasy artist Brian Froud!