A photo of this "dead leaf" (no, actually a dead leaf butterfly) came up on my Facebook feed today. Here's an article about it with several photos. Reading time 3 minutes. This dead leaf butterfly has a dazzling secret (australiangeographic.com.au) The "read more about camouflage" link is also a short article, not so many photos but interesting descriptions.
Here is sea slug camouflage, Elysia chlorotica. It even photosynthesizes. Elysia chlorotica, the slug that behave like a leaf - Encyclopedia of the Environment. Today's word is "kleptoplasty": Weird Science: Kleptoplasty | manoa.hawaii.edu/ExploringOurFluidEarth