The orange oakleaf butterfly (Kallima inachus), native to tropical Asia, is well named. The underside looks exactly like a leaf when the butterfly closes its wings, and it has wet and dry season forms that mimic the leaves of each season.
The butterfly stands out when its wings are open.
Watch it become a leaf as it flutters in place.
(photos from Wikimedia Commons; click on the captions to see the originals. video from Red Cache World on YouTube)