Soul Survivor G50
Reach round 15 in Nazi Zombies without getting revived. (Map Pack 2 only)
Easiest in solo.

Hammer Time G10
Repair 200 window boards in a single game. (Map Pack 2 only)
In the 1st round get 1 zombie at a window and hold your X for about 5 minutes.

Weapon of Minor Destruction G20
Kill no more than one zombie with a nuke. (Map Pack 2 only)
Try to get a nuke then kill all but the last zombie on a low round.

Big Baller G30
Earn 75,000 points in a single Nazi Zombie game. (Map Pack 2 only)
Easiest to get if you are in a glitch. Otherwise it is next to impossible
It | Impossible

Perk-a-Holic G20
Have all four perks simultaneously active in a game of Nazi Zombies. (Map Pack 2 only)
Easiest in a group of 4 players.

Big Brawler G30
Get 10 consecutive zombie melee kills before Insta-Kill expires. (Map Pack 2 only)
Easy with long knife or if you get lucky and get a 2nd insta kill before the first one expires.

It's a Trap! G20
Kill at least one zombie with three different traps in a single round. (Map Pack 2 only)
Flogger is not a trap. Use the flogger and 2 different electric barriers. Easier on a higher round (8 or so).

Fertilizer Man G30
Kill 200 zombies in a single game. (Map Pack 2 only)
Glitch or play legit.

Deadhead G30
Get 150 zombie headshots in a single game. (Map Pack 2 only)
Really hard to get. Id suggest you get a back window on 4 player with an MG.

Secret Achievements

Dead Air G10
Must have been a wrong number.
In the Comm Room there is a telephone. Hold X on it 3 times and it will ring then play the song from the trailer.