I love the typical warning colorations found in nature of this is a sphinx moth caterpillar, Hyles lineata. Sphinx moth larvae are called hornworms. They have a harmless but pronounced “horn” on their hind ends. The warning scary horn and the yellow and black eye adaptations are there to discourage potential predators. Despite popular belief about insects in general they don’t bite and are not poisonous to humans. However, they will wipe out your garden in just a couple of days with a large infestation.