Board Thread:Speculation House/@comment-10048743-20160211231306/@comment-1894551-20160216220049

It's cartoon physics. And all the way back in V1 Pyrrha said that even animals have Aura. So it's more than likely that Zwei, living with a family of Hunters, had his Aura unlocked so he wouldn't be a casualty if a Grimm attacked their home.