If you look like the leaf you’re sitting on, you are a lot less likely to be singled out as a meal by a predator. And, if you don’t get eaten, you are also more likely to live long enough to reproduce. Chances are, your offspring will also look a lot like a leaf too. Hopefully they don’t get eaten either.
Meet the satanic leaf-tailed gecko of Madagascar. Through millions of years of evolution its camouflage is so precise it really does look like a leaf. And if some sharp-eyed predator (birds, snakes, and rats) does happen to spot one of these geckos, the gecko will resort to plan B. They scream. Plan C is to leap to a new branch. But take a look at the picture. Can you spot the gecko? I’ll be plan A works most of the time!