Mary Beth: Oh how wonderful it is to be standing in the garden looking at those beautiful tomatoes, feeling proud of my babies and thinking of all the delicious meals I’m going to make. Mmm.

Almost ready to harvest
Wait! Something catches my eye. WTF?! Something is chewing big chunks of my plants! My tomatoes!
A shiver runs down my spine as I spot the culprit. A big, fat green monster — the dreaded Tomato Hornworm! And once again the game is on as I become obsessed with finding the beasts.

Hiding in plain sight. Those little nubby feet are strong!
They are the masters of camouflage so it takes a bit of practice to spot them. The best way to find them is to look for their poop; little black droppings on the leaves below where they munch. I track up the plant from the poop. Looking for the damage, squinting, concentrating…yes! Gotcha!!
Warning, the first time you see one of these guys it’s a bit freaky, they’re huge and kind of scary looking. Touching one will be the last thing you’ll want to do, but be fearless and get rid of it. And know that where there is one, there are others. So check each and every one of your plants carefully. Tomato Hornworms are eating machines that will devastate your plants in a day or two.

Look at all those little "eyes"! Eww!
I pull the pest off the plant (they have quite a grip) and throw it over the fence, or if I’m feeling ruthless I let the dogs have a go with it (hilarious, but not pretty). They’re way to big to squish, so I mostly take the coward’s way out and toss them as far as I can hoping that the birds will find them. Weird as it sounds it’s very satisfying to find those buggers.
So if you’ve been wondering what’s been eating your tomato plants, here is the likeliest suspect.
P.S. Technically these are Tobacco Hornworms, but most people identify them as Tomato Hornworms. They are the larvae of the Hummingbird Moth. The caterpillars can grow to 4 inches in length and are easiest to spot in the early morning or at dusk when the temperature is cooler. They’ll also eat potato plants, eggplants, and peppers. Here are a couple of links to more info — Colorado State Master Gardener and University of Minnesota.

Holly Cow lol! That things huge!
Whoa – I had no idea such monsters lurked!
Great picture!
When I was little, I remember seeing one of these on my Dad’s tomato plants and I thought we should move! Hilarious memories came back to me with this photo; my Daddy getting the five of us kids to try to look for them. Ick.
Yikes. Is there anything you can do to keep them away naturally?
[...] Watch for tomato hornworms, they’ll be chomping on your tomatoes this month. They’re hard to see; look for their frass (poop). Click for a pic. [...]
[...] Keep an eye out for those voracious green monsters, aka tomato hornworms [...]