Luna Moth
Look closely -- those aren't leaves! This is the elusive and cleverly disguised Luna Moth. One would think this large silkworm moth would be easy to find, but they only live in moth form for about a week (they have no mouth, so every Luna Moth ultimately runs out of energy and dies). And besides, as you can see, even if one is present it can be very tricky to find!
Credit: Michael Schramm/USFWS. Original public domain image from Flickr