As mentioned, the dreaded tomato hornworm. They won't kill the plant if
found soon but they sure make it look ugly fast. Look in the area of
the damage and it'll be closeby, usually hanging upside down under a
leaf or along a stem. Cut off the leaf below where the critter is and
dump them both, or pick them off with needle nose pliers. Only problem
there is they usually have a good grip on the stem, so best to cut it.
I've done this for years and not lost a plant yet.

Now for the real question, where oh where do they come from and go to?

Craig wrote:

Hello All,

I was a little disturbed to find half my tomato plants leaves eaten off this
morning. Seems some sort of critter picked all the leaves clean off. He ate
all the tomato leaves off the plants that we not in cages, I had intended to
stake them. My neighbor had an opossum in their yard last year. Maybe it was
another opossum? I've never had anything disturb my tomato plants before. It
looks like he might have tried a pepper plant but didn't like them. Garlic,
onions, radishes, green beans, and lettuce all we untouched. Any suggestion
on how to save my remaining and replacement tomatoes?

Thanks in advance,

Craig
Staten Island, NY