In all seriousness, there is too much information missing. How high is the camera? Pictures before and after? What is the camera attached to? WHERE is this?
So, what do we know for sure? You can see both sides, like it was really skinny, like a leg or arm, but if the camera was, say, 5 feet off the ground, then I don't think it would be a leg. The blurry leaves in front of it look tiny, like evergreen leaves or some sort of grassy weed (compare to background flora) but if that's the case then the blurry brown cannot be very big at all. At least we know about how wide it is, six inches, maybe? It's very close to the camera and if the camera is strapped to a tree then it must have crossed in front of it. BUT, the slight motion blurring that I can make out would suggest an up/down motion. If I had to hazard a guess I would say that a small animal jumped over the camera on the way down from the tree but again, without knowing the answer's to the above questions it will be almost impossible to tell. Of course, it could always be a deliberate hoax.