Caterpillars change and grow by spitting their skin. A new, larger one is under the old, tight skin. They change through several instars (stages). Then they weave a cocoon and change into a moth. This is the caterpillar of the Pandorus Sphinx. It is a beautiful, large moth, a feeder on night-blooming plants (such as the Moon Flower Datura in the thumbnail photo) with a proboscis (tongue) about four inches long.

The Pandorus Sphinx has good protective coloration because it blends in with its surroundings.

Pandorus