@Lion_99 16 July 2021 more from that month

There are green reptiles, insects, fishes, amphibians but no green mammals. What's the for this? Weeeeel…..The sloth is sometimes green because of its a symbiotic relationship with green algae that inhabit its fur/hair – whatever it is. It presumably adds a touch of camouflage, which added to the lack of movement that sloths generally indulge in means that it's more difficult to see and therefore to kill.