This crawling piece of crap was not on any of my tomato plants, a circumstance for which I am truly grateful.
Instead, it was on my experimental potato plant in a garbage can -- in the late spring, I'd put several sprouty russet potatoes in a garbage can, covered them with a few inches of dirt, and have been adding decorative bark to the growing stems.
It's a failed experiment -- the stems showed little or no interest in making tubers. I may have started the experiment too late for success. Perhaps I'll try again next year.
Odd that this hornworm chose the potatoes instead of the tomatoes, but I'm glad it did. My ire was much less. How I wished that I had a chicken to eat this bug! But since it was on a worthless potato project, I merely clipped off the stem and put it in the City garden stuff recycle bin, where it can be fertilizer for one of the many excellent City compost utilizations in the future.
Haha, hornworm, you lose.