A Hummingbird Hawk Moth Caterpillar (Possibly!)

I found this caterpillar on our privet hedge, Friday (8th September):

I tried looking up what he was, from last weeks experience I could tell he was some kind of hawk moth, but which one? He didn't have any real stand out features except his spots and a faint stripe down his back joining at his tail. All the photos I saw online had features that were a lot more distinct. So my conclusion is that he is a Hummingbird Hawk Moth. (Which would make sense as we had 2 resident on our lavender all summer!) What still doesn't make sense is that it was eating the privet hedge, but looks nothing like a Privet Hawk Moth. I don't know!!!

A naf photo but the only one showing the stripe

So, I found out what they need to pupate and decided I would keep him just to satisfy my curiosity. And just in time too as Sunday morning he had stopped eating and looked quite dramatically different:

Looks more like a puppy dog!?!

He stayed in this position for quite a while getting darker and darker:

When he finally moved he started flicking about and staying in this position. It looked like it was definitely time to pupate:

I found a clear pot and put some earth in the bottom with some dried leaves on top as I wasn't exactly sure what he would prefer. This burying yourself to pupate is all new to me! Then some privet as a climbing frame:

It wasn't long before he was in the pot rummaging around for good spot. It was late afternoon on Sunday (10th September) when he finally disappeared. Now I have placed netting over the top of the pot and placed it in a cool place. I guess he will overwinter and I will have to wait until the weather warms up next year to see what he really is!