hmmm.
The first of my zombies are upgrading into Hungry Zs 
Early summer, after 28 days of spring. I was stripping a humvee for its ups charger and decided that I may as well replace the inferior parts I had used to patch the holes while I skilled up.
What started as a group of like 5 Greenies and a brute soon turning into a constant trickle of single zombies. Then one had the audacity to bang on a nearby car before I could get to him.
A horde from the south came up. A trickling horde of 5 to 10 at a time. Eventually I had to use my emergency molotov. That only pissed off a nearby necromancer.
So I swallowed my pride and hopped into the humvee. I backed it up, and rammed through them with my full water tanks and I backed up over the ones I missed and then I did it again.
All told, over 100 bodies lay, some pulped but all showing the wounds of a fire axe as it cleaved into them.
As I finsihed harvesting the composite armor, a zombie got up, a Hungry look in its eyes. For he had evolved into a new kind of Greenie. A Hungry Greenie.
= = = = =
So its nice to confirm that after 1 season the “14” upgrades take place. Knowing that, I think I may push up the greenies a little more. Honestly, although I made the mod so I didnt have to keep updating the jsons, Ill temper it to other peoples playstyles too.
I was using a fire axe, have 4 melee and 3 bashing. Im a slow learner, so make of it what you will, but the Z took several hits.