It's a tomato hornworm - the caterpillar of the hummingbird moth - and those white rice-like attachments are the eggs of a parasitic wasp that will literally devour the worm when they hatch. The horn, by the way, is on the tail of the caterpillar. We've never had these before. I think most current tomato hybrids are bred to resist this pest. I'm wondering if we didn't get this infestation from an heirloom plant we picked up at the Master Gardener's sale. It might be that that variety is not resistant to these pests.
The garden is not doing that well as we have not had any significant rain for a while. I lost my early crop of blackberries to the heat. We've been trying to salvage the current crop. I've been getting just about a quart every few days. I can tell you that there certainly is an abundant crop of mosquitoes though!!!