Robjump

Obstacle Building Complete all test chambers in the Excursion Funnels co-op course

Prize Catch Finish Operation: Off the Hook

Can't Touch This Dance in front of a turret blocked by a hard light bridge in co-op

Wanted You achieved the highest personal rank possible in multiplayer.

You Saved Science Complete all test chambers in all courses of co-op

Auf Wiedersehen Petrovic You won in all variations of multiplayer games.

Empty Gesture Drop your co-op partner in goo while they are gesturing by removing the bridge under them

Four Ring Circus Enter 4 different portals without touching the ground in co-op

Critical Hit! Complete the Seta River Killers

Asking for Trouble Taunt GLaDOS in front of a camera in each of the five co-op courses

Slippery Slope Complete the "Black Ice" Special Ops mission on any difficulty.

Shotgun Diplomacy Complete the Special Ops mission "Negotiator" on any difficulty.

Iron Grip Never lose a cube in Chamber 6 of the Mass and Velocity co-op course

Party of Three Find the hidden companion cube in co-op test chamber

Portal Conservation Society Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements

One-Four-One Complete the "Kill Switch" Special Ops mission on any difficulty.

A Baker's Dozen Run over and kill 13 enemies with the snowmobile in the "Black Ice" Special Ops mission.

Taking A Liberty Sorry for taking liberties with your time.

Ice in Your Veins Complete the "Black Ice" Special Ops mission on Veteran difficulty.

Triple Crown Solve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each

The Might of the Monkey! Use the Monkey Bomb. (Map Pack 3 only)

Locksmith! Open all doors in the map. (Map Pack 3 only)

Don't Tread on Me Complete the "Iron Clad" Special Ops mission on any difficulty.

Still Alive Complete Course 4 with neither you nor your co-op partner dying

Stay Frosty Complete the "Arctic Recon" Special Ops mission on any difficulty.

Wacker Packer! Upgrade any weapon in Pack A Punch. (Map Pack 3 only)

Hammer Time Repair 200 window boards in a single game. (Map Pack 2 only)

Helipocalypse Destroy 6 helicopters in the "Kill Switch" Special Ops mission.

Weapon of Minor Destruction Kill no more than one zombie with a nuke. (Map Pack 2 only)

Skilled Negotiator Complete the Special Ops mission "Negotiator" on Veteran difficulty.

Der Electrician! Link all teleport pads before round 7. (Map Pack 3 only)

Dead Air Must have been a wrong number. (Secret Trophy)

EMPressive... Complete the "Kill Switch" Special Ops mission on Veteran difficulty.

Handle with Care Complete the "Special Delivery" Special Ops mission on any difficulty.

Apex Complete the "Vertigo" Special Ops mission on any difficulty.

Not on My Watch Rescue all the hostages in the Special Ops mission "Negotiator."

Elevate Your Senses! Activate the Fly Trap. (Map Pack 3 only)

Not a Scratch Finish with your tank at full health in the "Iron Clad" Special Ops mission.

Siege Complete the "Light 'Em Up" Special Ops mission on any difficulty.

Untouchable Use only one self revive care package in the "Special Delivery" Special Ops mission.

High Roller Complete the "Iron Clad" Special Ops mission on Veteran difficulty.

dr0n3d Complete the "Arctic Recon" Special Ops mission in under 3:30.

Fertilizer Man Kill 200 zombies in a single game. (Map Pack 2 only)

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

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

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

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

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

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

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