Eumorpha achemon sphinx moth caterpillars
Was inconspicuous on Juniper bark until it spread its wings
This stumped me till I found pics on your site. I think its an Achemon Sphinx caterpillar, SW Missouri
Found this guy on a Virginia creeper, so figured I might have found the ID that I was looking for. It seemed more of a rusty red than a brown color though.
Achemon Sphinx caterpillar on grape vine, Caney Creek, Stilwell OK. mid Sept.