This deep orange-brown beauty is one form of a somewhat common type of sphinx moth larva -- the other form is green, and while beautiful, is not quite as striking as this one. These caterpillars belong to the same family as "hornworms," and they have a horn on the tail end as young larva; older caterpillars have a glassy button instead of a horn. This caterpillar in the illustration may be a tropical version of the North American pandorus species -- it's a little hard to tell. But if you find one, you can be sure you've found a truly special insect.