I saw a Swallowtail butterfly (Spicebush Swallowtail - Papilio troilus) laying an egg on a Sassafras leaf, so I thought I'd photograph it every few days until it became an adult. Here's the result; of course my very compliant model was released back to the wild when it finally emerged.
It's a cruel evolutionary joke when environmental selection pressure has made you look like a bird shit (it even sits on top of the leaves to may this pretense more credible) to discourage others from eating you while you're a baby! However, when it's too large to pretend to be a poop it then sheds it's skin and looks like a small snake. In essence the birds have molded this caterpillar with their dislikes and fears.