These coloful and spiky fellows are silkworms of the species Apatelodes pudefacta. The large, rather fluffy and spiky-winged adults are often mistaken for hawkmoths, and the tufted caterpillars can resemble tussock moth or dagger moth juveniles. In fact, the genus name “Apatelodes” literally means “looks like Apatela,” a reference to the old genus name for dagger moths. (“Apatela” later became “Acronicta.”)
This particular species gets two obscure references in its name. The species name “pudefacta” means “ashamed” and is likely a play on the related species “diffidens” meaning “diffident.”
The moral of the story is that scientists cannot be trusted to name things in non-confusing ways.