Tetrio Sphinx, Giant Gray Sphinx, Frangipani Hornworm, Plumeria Caterpillar

More than a dozen of these nearly 6" long caterpillars were clustered together at eye level on a trio of small trees. They are said to bite, but more than that, they have a nasty taste and predators avoid them. I noticed that their tails (tiny, black, at the rear) wag and wiggle like a dog tail. They morph into a sphinx moth.