When I woke up into the hellish world of DayZ I would have described these zombies as Romero Zombies. Slow, easy to kill and only really dangerous in large groups. Something happened... They began to change. I believe that something in their brains is starting to wake up. They are learning, becoming faster, stronger, more persistent and harder to kill. They are more like the zombies from the return of the living dead movies I use to watch when there was still power. I fear for the future, they will keep mutating and learning I'm sure of it.....