The giant sloth is green.....algae growing on the fur makes it green.....but you knew that.
Yes, I did. I don't count algae as a mammal...
I also don't count the green monkey, it's not really green, more of a washed out greenish gray.
I'm looking for a true green, hide in the trees and ferns green, same as every other non-mammal has from fungi on up...