He sat looking at me in my garden. When I went to touch him he lunged at me like a snake! He has a nice barb on his tail and I like him. I call him Jabba. What is he? link
You should ask the doctor! I'm sure he will love that creature.
But if he is busy, go to a near university and talk with a biologist, show him/her the picture, and let's see what he is.
I've had one of those in my garden, something like 15 years ago. I've never seen one since, so it stuck in my mind as strange, but I recognize it from your picture straight away. It seems to be some kind of caterpillar, but I don't know what kind.
Funnily enough one of these turned up in my house a few days ago, although it had a greener colouring, and it tapered at the head end more.
Never seen one ever before and am equally curious to find out exactly what it was.