Is this creature a tomato hornworm caterpillar? Are these white growths on it the larvae that will mature into braconid wasps?
Great image and this is actually a good thing!.
The white projections are the larvae of the braconid wasp, Cotesia congregatus. Larvae that hatch from the wasp’s eggs, which are laid on the hornworm, feed on the inside of the hornworm until the wasp is ready to pupate. Such “host” hornworms should be left in the garden in order to conserve the beneficial parasites. The wasps will kill the hornworms when they emerge from their cocoons. They will also seek out other hornworms to feed upon and kill.