Think it was around 1963. A couple of friends and myself went mushroom hunting very early one morning in the countryside just outside Marlborough. As we were walking down a muddy lane a very mangy old cat appeared out of the hedge and stopped in front of us, just staring at us before slowly walking off in front. Every now and then it would stop, turn round to see if we were still following, and then it would set off again. After about ten minuets it slipped through a farm gate, stopped on the other side watching if we'd follow (which we did) before it headed up a hill. At the top of the hill were a couple of round barrows; the cat climbed one of them and waited for us to join it. The three of us and the cat watched each other for a few seconds and then, without warning the cat, front paws and claws extended, leapt at the face of one of my friends; he managed to turn his head away in time and the cat landed on his shoulder before jumping off and running away.

That's excellent stuff, the second photo there is especially smart :)

I'd love to think that the white cat could oneday be incorporated into some future folklore relating to the stone. Like Mr Watts hints at below, the cat must surely be the Witch's familiar ;)