Socking big caterpillar

We came across this socking big caterpillar on the footpath to Walberswick beach, by the AONB reedbeds.

At first we thought it must be a child's rubber toy, it was so very big and colourful. But then it moved..

It was as long and as wide as my ring finger and beautifully green, decorated with a pattern of red-orange dots set in lines - and very very active.

I have cautiously identified it as an Emperor Hawk moth caterpillar. Gosh, I would love to see the adult - but in the meantime this was special enough.

If anyone can confirm this I would be very grateful. I am still recovering from the discovery that the bumble-bee I blipped last month was actually a Large Bee-fly, Bombylius major.

Shucks