The Z-Whacker is a weapon featured on Z Nation, first encountered in season 1, episode 1, "Puppies and Kittens". During the season 2 finale, episode 15 "All Good Things Must Come to an End", a fight between Addy and a member of the Zeros causes the weapon to split into two pieces.
Created by Sketchy McClain, it is an aluminum baseball bat reinforced with aluminum spikes near the top and extended a couple of inches from the bat body. Six spikes are evenly spaced around the circumference with one sizable spike at the end of the bat.
It is created to be light weight, and to kill the brain of a zombie without getting stuck in the skull.
According to Sketchy, the spikes were forged from aluminum beer cans for a lightweight feel.