This is the M48 Tactical War Hammer made by United Cutlery (available HERE for $50 -- and buy me a ninja sword while you're at it). It has a hammer skull basher on one side and a skull splitting pick on the other side. What side would you rather get hit with? If I had to choose I would rather get hit with the handle.
Keep going for a video of the hammer bashing and puncturing things.
Thanks to James G, who agrees half the people buying zombie apocalypse weaponry will wind up killing themselves with it due to lack of training and experience. That is just factual.