Prisoner Zero?

So we have had outer-space rhinos, nasty feline nuns and now it looks like this mutt may be The Doc's latest enemy! This dog is supposedly a shape shifiting alien called Prisoner Zero that the Atraxi are after. The Atraxi are space police and if other rumours are to be belived our planet culd be at risk if he isnt returned to them!Im not quite sure how this dog fits in with the crack in the wall and other pictures of a woman and her children loking creepy like this man holding the Dog. This may not be the dog that is Prisoner zero as Matt Smith has been seen crouched down talking to something that isnt there when filming meaning that it could be CGI. Anyway enough speculation theres only 3 days left!