OmegaMustard

Skilled Adversary In IX have a Challenge banner with all 9 medallions

Swimming with the Fishes In Voyage of Despair, kill 50 zombies that are underwater in a single game

Big Brawler Get 10 consecutive zombie melee kills before Insta-Kill expires. (Map Pack 2 only)

Pea Shooter Kill a Rhino with only a pistol in Nightfall in Regular or Hardcore difficulty.

Great Success Gain S+ on all U.S.S. missions on Veteran or Professional difficulty

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

Go for Gold! In Onslaught, acquire seven gold chalices

I’ve seen some things… In Kino Der Toten, visit every location the teleporter can take you to.

Atomic Obliteration - Complete all the Challenges

Seal the Deal Complete a Triumph Seal.

Pack-A-Punch-ectomy In Revelations, recover the Pack-a-Punch machine from its abductor.

Pursuit of Knowledge Filled 80% of the Datalog.

Things That Go Ka-Boom Learn how to craft Exploding Arrows

Electric Whisper Learn how to craft Electric Arrows

Guilty as Charged Complete a Murder Circus Finale with Chief Justice.

Moneybags Have 15000 credits in the bank in Outbreak.

Perkaholics Anonymous! Survive until round 20 without buying a single Perk. (Map Pack 3 only)

Gimme Five Attain Level 5 with all Murder Circus contestants.

Most Dangerous Game Complete a Murder Circus Finale with Artemis.

Deer in the Headlights Stab five stunned enemies in a row in the "Light 'Em Up" Special Ops mission.

40 Knives! Kill 40 zombies with the bowie knife. (Map Pack 3 only)

Viva La Reina Complete a Murder Circus Finale with Consuela.

All Star Get 100 Stars in S.T.A.R. Lab Mode

Around and Around We Go Perform every level interaction once

Living the Dream Complete a Murder Circus Finale with Daniel Li.

Happy Trails Complete By the Trail of Our Dead

Have you tried turning it off and on again? Complete Terminal Error on any difficulty.

The New Time-Master Beat all of Nefarious Tropy's times in Time Trial Mode.

Is everyone here? Unlock all characters from the original roster.

Burgle Burgle Burgle Steal 10 kills from a teammate in Outbreak.

Campaign Kitty Obtain all 108 medals on the original Arkham City campaigns (as Catwoman)

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

Frequent Flyer! Use the teleporter 8 times. (Map Pack 3 only)

In the Belly of the Beast In Zetsubou No Shima, survive getting consumed.

Kali Ma Complete Abaddon Asylum on any difficulty.

Throttled Survival Kill the Breeder while using a Relic in Nightfall in Regular or Hardcore difficulty.

Sub Zero Complete the "Arctic Recon" Special Ops mission on Veteran difficulty.

Behind the Curtain Complete Beckett's story

Sleuth Unlock all intel (videos and audio files)

You Died Alot Get killed by Jason 100 times.

Total protonic reversal Complete Return to Hell on any difficulty.

Survived Mayday Kill the Kraken for the first time in Mayday in Regular or Hardcore difficulty.

Targets Acquired Get past the first gate in Awakening in Regular or Hardcore difficulty.

Gong like the Wind In IX, defeat all 8 challengers summoned by a gong within 5 minutes

Der Meisterbogenschuetze In Der Eisendrache, obtain all of the ancient bows.

Taking Flight In Gorod Krovi, ride a Dragon.

New Superpower Complete all China Rising Assignments

None more hard Complete the Campaign on Nightmare difficulty.

Stowaway In Voyage of Despair, spend 5 consecutive rounds in the Cargo Hold

Discriminating Buyer Use exactly one of each care package in the "Special Delivery" Special Ops mission.