Unwelcomed Insects: Cabbage Leaves

My first problem in the Pizzabox: aphids and a hungry caterpillar? All of my cabbage plants are under attack. Something is biting through most of all of my  cabbage leaves. I have cucumber leaves... maybe they are too hard. There are two types of lettuce, tomato plants, basil... no.. this critter is targeting only all my cabbages, except one! And that lone cabbage that hasn't been bitten has aphids.  Aphids... that's another post. Who is eating through my cabbage and how can I find someone to eat him?