lHELP wanted please from any keen lepidopterists, entomologists or botanists.

I was mowing my parents' garden in St Helens Road when I came across the biggest caterpillar I have ever seen. It was about three inches long and about half an inch thick and coloured beige and black/brown.

It reminded me of the ones used in cartoons that are illustrated sitting on a mushroom with a hat on.

I picked it up and placed it on the gravel path nearby. It wasn't happy and let me know it. It looked at me with such a pleading little face that I just had to pick it up and move it into the greenery. I was quite taken aback. Can anyone tell me what it is?