Here's the list:
Burning Irony
Kill 15 Husks with the Husk Cannon
Highlander
Kill a Scrake, a Fleshpound, and the Patriarch with the Claymore Sword within one map
Bloody Yanks
Kill 1 specimen ONLY while expending a full M4 Assault Rifle magazine
Finish Him
Hit a Scrake with the M203 Rifle grenade to kill him
I love ze Healing not ze Hurting
Heal others for 3000 points of health with the MP5 SMG
Italian Meat Pasta
Kill 12 zeds with a full magazine from the Combat Shotgun
Feeling Lucky?
Kill a specimen with every shot from your Revolver for one magazine
We Have Ourselves a Cowboy
Hold dual 9mm, dual hand cannons and Dual Revolvers
Snow Cone
Beat Ice Cave on Normal
Stay Frosty
Beat Ice Cave on Hard
On the Rocks
Beat Ice Cave on Suicidal
Anti Freeze
Beat Ice Cave on Hell on Earth
A Bloody Christmas Carol
Kill 15 XMas Clots, 5 xmas Stalkers, 5 XMas Crawlers, 1 XMas Siren and 1 XMas Bloat.
Burning Irony
Kill 15 Husks with the Husk Cannon
Highlander
Kill a Scrake, a Fleshpound, and the Patriarch with the Claymore Sword within one map
Bloody Yanks
Kill 1 specimen ONLY while expending a full M4 Assault Rifle magazine
Finish Him
Hit a Scrake with the M203 Rifle grenade to kill him
I love ze Healing not ze Hurting
Heal others for 3000 points of health with the MP5 SMG
Italian Meat Pasta
Kill 12 zeds with a full magazine from the Combat Shotgun
Feeling Lucky?
Kill a specimen with every shot from your Revolver for one magazine
We Have Ourselves a Cowboy
Hold dual 9mm, dual hand cannons and Dual Revolvers
Snow Cone
Beat Ice Cave on Normal
Stay Frosty
Beat Ice Cave on Hard
On the Rocks
Beat Ice Cave on Suicidal
Anti Freeze
Beat Ice Cave on Hell on Earth
A Bloody Christmas Carol
Kill 15 XMas Clots, 5 xmas Stalkers, 5 XMas Crawlers, 1 XMas Siren and 1 XMas Bloat.