"I have literally just seen it too whilst out on a run (12/10/2014 at 1pm)!
I was running along Rickman Hill Road in Coulsdon, when I saw what looked like a large jet-black dog cross my path about 100 yards ahead. I couldn't get a glimpse of its head but had very large paws and a long tail that curled upwards at end. Having originally assumed it was a dog I carried on running, expecting there to be a driveway that it had walked into, but it was just dense woodland!
Just arrived back home and searched online and found this post, turns out I'm not going mad!"