Here is the full list of all 31 Zombie Kill of the Week - there are Reborn achievements.
Zombies are not ment to fly.
Get 100 headshots in one match.
Help your friend in need.
Own atleast 5000$ in one match
Fight your way to round 20.
Get 5 meats in a single game from the fridge.
Kill 15 zombies with a katana, and 25 with saw in one match.
Get promoted to rank 10.
Get promoted to rank 30.
You have played ZKW for an hour.
You have wasted 5 hours of your life.
And still going?
Go see your friends!
Slaughter 5000 zombies in total.
Slaughter 10 000 zombies in total.
Slice 53 zombies in one match.
Encounter all 3 tanks, and get them killed.
Grill 50 zombies with flame in a single match.
Get the GiGaGirlGannon, and kill 10 zombies within 10 seconds.
Get a shotgun, and make 20 zombies crawl in front of you.
Open all areas in a single match.
Get yourself killed with a grenade. Dumbass.
Stand still for 30 seconds, wondering about your life.
Find the fridge and make it disappear. Repeat 3 times.
Kill the zombie bear before he takes your money.
Survive 4 minutes in Abandoned Hospital. (Challenge mode)
Survive 4 minutes in RedSnow. (Challenge mode)
Survive 4 minutes in Night At The Mall. (Challenge mode)
Survive 4 minutes in Arise. (Challenge mode)
Survive 4 minutes in Area 73. (Challenge mode)
Survive 4 minutes in Homerun. (Challenge mode)