Clearly the work of people with too much time on their hands, but still damn funny:
Michael Bublé Being Stalked by a Velociraptor
The best ones are where the velociraptor isn't immediately obvious, or where you can only see its shadow or its reflection or a tiny part of it.
But this one is my absolute favorite. (I've stood on that exact street corner, BTW. I wasn't stalking Michael Bublé, though; I was taking a photo of P under the Late Night marquee.)