Spotting

I believe this is actually a tobacco hornworm, not a tomato. They look very similar and can be found on the same host plant, but vary slightly in their markings and the color of the horn. The link I posted to BugGuide explains it pretty well.

actually i can see now you have a pepper in the photo, they also attck them, worst on tomatoe pepper, potato, and eggplant!!

These can be a big pest! hope they arnt on your tomatoe plants!