Right now, I’m grinding my melee and unarmed skills against an armored zombie, which currently takes the top spot as my practice dummy of the year. With insanely high armour and average DPT, you can beat up the zed all day long and takes almost no damage as long as you’re wearing sufficient armour.
I mean seriously, it took point blank barrage of my A7 laser rifle to the face without taking a scratch. Though you can actually damage it with electric attacks. I killed the previous three armored zed with the electroshock unit CBM.