Tobacco Hornworm Caterpillar
Found this one in my backyard garden eating my tomato plant. The species is Manduca sexta. It will become a Hawkmoth. It looks to be in the last stage (fifth instar) of molt. When you rotate the photo it looks like nature intended this thing to look like a dinosaur showing his teeth. They apparently eat about as much as a dinosaur would. The absence of leaves on one of my plants gave him away.