Took these pictures Sunday morning and at first I thought it was a Dark Umber caterpillar. Not so sure now, because at around 35 - 40 mm it seems a bit large, it wasn't doing that back-arching thing and I don't know of any buckthorn (Dark Umber food plant) in the vicinity. And, yes, that IS a dollop of horse muck it's crawling across.
So, if it ain't Dark Umber, what is it?
