www.ukbutterflies.co.uk

I found this caterpillar at the bottom of my horses water trough, I thought it had drowned but fished it out and brought it home to try and identify. It is still alive so PLEASE HELP!!! Anyone know what it is? The fields are chalk downland ( North Downs ).

looks like it could be, i think i can make out the black dashes down the back, the green form of large yellow underwing moth.

Thanks Chris I have put up more photos showing the dark markings and I have looked up the moth and its caterpillar pics. I am pretty sure you are right and will return it to my field in a safe as possible place.

Have to say that I don't recognise it as a butterfly larva.