Black swallowtails :-)
I found some of these guys eating my parsley and dill plants:
They will become these lovely creatures:
= new reply since forum marked as read
Sometimes I bring them inside and raise them, to protect them from predators (mostly birds). Course I love the birds as well-- just don't want them to eat my future butterflies until they at least have a chance. 
I only had the a couple of caterpillars that ate all the parsley and then disappeared. I looked around in the surrounding foliage for a chrysalis but didn't see anything. I hope the birds didn't get them. I enjoyed them while they were here, though, and the parsley grew back. I also found one in the dill weed. 
And another smaller one who is dead in the dirt so I am going to take a small fish tank and set them in it. I am surprised by how fast they grow. Just yesterday they were
half their size. I bought another parsley plant for them.
Luckily it's organic and on clearance at the grocery store. The butterflies love my compost pile which I am not very good about turning regularly. The raccoon has been eating my old squash. I'm just surprised I have not seen the opossum there. I did come across a black woolly, also known as a giant leopard moth caterpillar. 
