...The Harder They Fall - kill the Top Player in a match 5 times in a row
1bullet2kills - 1 collateral damage kill
1st Lt. - earned by leveling up
1st Sgt. - earned by leveling up
2fast - 15 kills with Sleight of Hand perk enabled
30 Something-30+ kill strek
Absentee Killer - Gain a game winning killcam with a sentry gun (Absentee Killer challenge)
Accident Prone - Fall 15 feet or more and survive (Base Jump challenge)
Airborne - call in 3 pav lows(challenge)
All Pro - Headshot 2+ Enemy's with a Single Sniper Bullet
All Your Base - Extreme Cruelty challenge
Angel of Death - call in 10 AC-130's (challenge)
Armed and Dangerous - complete Bling Pro VI challenge
Art of Stealth - complete 250 close range kills with the Ninja perk enabled
Backsmasher - kill someone from behind with the riot shield (Back smasher challenge)
BOOM! Headshot - 25 headshots with an LMG
Backstabber - Stab an enemy in the back with your knife (Backstabber challenge)
Big Brother-call in 100 UAV's
Bite the Bullet - Get 1000 kills using Stopping Power
Blindfire - Kill an enemy while you are still dazed by a flashbang (Blindfire challenge)
Bling Bling - Get 450 kills with Bling perk enabled (Bling V challenge)
Blood Brothers - Win 15 (core) Team Deathmatches (Operations challenge)
Blood Money - Get 5 Payback kills with headshots (Color of Money I challenge)
Blunt Trauma - 2 kills with Riot Shield
Bombshell - kill the bomb carrier (challenge)
Bow Down-Have the highest KDR at the end of a match
Broken Arrow-Have the highest KDR at the end of a match
Bullseye-get a semtex stick
Catch Shrapnel - get 5 claymore kills
Charity Case - call in 50 Care Packages, Sentry Guns or Emergency Care Packages
Chick Magnet - Call in 2 EMPs (Blackout I Challenge)
Cloak and Dagger - get 5 throwing knife kills (Carnie I challenge)
Commander - earned by leveling up
Companion Crate - call in 25 Care Packages
Completely Numb - Take enough damage to normally killl you with painkiller activated.
Concussive Barage - Finish off a kill with a stun grenade(challenge)
Counter Intelligence - get 250 kills with Scrambler perk on(challenge)
Crackin' Skulls - Get 25 headshots using an Assault gun (challenge)
DZ Clear - call in 25 care packages
Deadline - Use 100 killstreaks while using the Hardline perk (Hardline Pro Challenge V)
Devestater - kill every member of the enemy team (Tango Down challenge)
Dictator - Every bullet in an LMG clip hits an enemy (challenge)
Dishes are Done - Get an assisted suicide kill
Dish the Rock-Most assists in a game
Disruptor - get 5 kills with Scrambler perk enabled (Scrambler Pro 1 challenge)
Double Down-Get 25 kills using the Bling perk
Drifter - destroy 1 car
Drone Killer - Get a winning kill with predator missile (challenge)
End of the Line - End Game II challenge
Enemy of the State - be the last man standing and get 3 kills
Enemy with Benefits - Kill two enemies by sticking a semtex to one of them
Epic-Kill the whole enemy team within 10 seconds
Explosive Ordinance - 15 search and destroy wins (challenge)
FNG - start out with this
Flying Tank - Call in 10 pave lows (challenge)
Flyswatter - shoot down a chopper
Frag Out - get 10 grenade kills
Friends With Benefits - complete The Resourceful challenge
Full Arsenal - 15 kills with One Man Army activated
Gen. - earned by leveling up
Get Real - win 1 Hardcore Team Deathmatch (Hardcore Team Player 1 challenge)
Get to the Choppa! - Call in 3 chopper gunners (challenge)
Ghilie in the Mist - 100 One Shot Kills (2nd Ghillie in the Mist Challenge)
Ghostrider - Kill 3 enemies with a predator missile in one launch
Givin' Static - get 5 counter UAVs
Global Thermonuclear War - call in 2 a tactical nuke(tactical nuke challenge)
Godhand - call in 3 (?) AC-130s
Grassy Knoll - Get the Grassy Knoll accolade (most time spent prone)
Hair Trigger - Hair trigger accolade
Hard to Kill - get 2 kills on Last Stand
Hardcore Only - Win 10 HC TDM games
Headrush - 5 headshots with an SMG
Heartbreaker - steal x amount of enemy crates
Hello "Its Personal" - Injure an enemy with a weapon and kill him with the throwing knife
Hi Def - Get the game winning kill cam with a chopper gunner
High Caliber - Finish an entire match without dying
Highlander - Go a full length match without dying
Hijacker - Take 10 enemy care packages (Hijacker I challenge)
Hot Shot - Defuse 2 Bombs
ID Thief - get a payback kill with Copycat enabled
Impaler - get two melee kills with Commando enabled
Invincible - Regenerate from enemy damage 5 consecutive times without dying (challenge)
Invisible - Take out 3 enemy killstreak rewards while using coldblooded (challenge)
Jack-in-the-box - Kill somebody within five seconds of spawning at a tactical insertion
Joint Ops - tied to the assists challange 'Point Guard'
Jump Jet - call in 5 harrier airstrikes
Klepotomaniac - Kill 3 enemies with 3 different weapons in a single life
Live Long.. - survive for 5 minutes
Living Dead - for surviving and getting back on your feet after you've been downed to final stand
Lone Wolf - Win a free for all match (challenge)
Low Profile - get 15 prone shots (Prone I challenge)
Mach 5 - Every bullet in an SMG clip hits an enemy (Mach 5 challenge)
Maj. - earned by leveling up
Martyr - get 1 kill with martyrdom
Mastermind - 15 kills with a claymore (challenge)
Mmmm... Brains-complete the two barrels challenge
Money Shot-get 25 py back kills
My Lil' Pwny-prestige and then get 50 kill with a silnced weapon
NBK - get 3 Longshot kills in one life
New Jack - get a Payback kill with a throwing knife(ATM challenge)
Ninja - complete commando challenge V
No. - shoot enemy player as they are cooking a grenade
Noob tuber - kill an enemy with a grenade launcher without detonation (Ouch challenge)
OG - Get a game winning kill with a helicopter (challenge)
OMFG - Kill an enemy, pick up his weapon, then kill him again with his weapon (Cruelty challenge)
Omnicide - Kill the entire enemy team within 10 seconds (challenge)
Omnipotent - Have the highest K/D ratio at the end of a game 25 times
One Inch Punch - get 750 kills using Sleight of Hand
Overwatch - Call in 5 UAVs (Exposed I challenge)
Owned - Get a game winning kill with a riot shield (Humiliation challenge: Owned)
Perfectionist - for emptying a sniper clip without missing a shot (Hit an enemy with every round you fire from that clip).
Philanthropist - let 100 teamates take your care packages
Pineapple Express - get 25 grenade kills
Plane Whisperer - get 2 air strikes in one game
Plastique - get 5 kills with C4
Preemptive Strike - Complete Hardline Pro I challenge
Pro Gambler - call in 100 total airdrop crates (Airdrop Inbound II challenge)
Public Enemy - Play Team Deathmatch and get the top score overall (MVP Team Deathmatch challenge)
Pushin' Daises - fall 30 feet or more to your death (Goodbye challenge)
Pyromaniac - destroy 2 enemy equipment
Rainmaker-25 kills with the predator misille
Rain of Fire - Predator missile challenge I
Reign Down - Call in 5 attack helicopters (Attack Helicopter Veteran I challenge )
Rejected - Destroy 15 enemy equipment (challenge)
Reloaded - Use Scavenger 10 times to resupply (Scavenger I challenge)
Remote Viewer - 5 Bullet Penetration Kills
Rival - kill the same enemy 5 times in a single match
S.S.D.D. - earned by leveling up
Sgt. - earned by leveling up
Share Package - have someone on your team pick up your emergency drop
Sidekick - Kill 3 enemies with secondary weapon in 1 life
SIGINT - Call in 25 Counter UAVs (Interference 2 challenge)
Silent Strike - Complete Ninja Pro I challenge
Skeet Shooter - kill one enemy that's in mid-air (Hard Landing challenge)
Smash Hit - Get a 3 Killstreak with a riot shield
Speed Demon - run 2 miles with Light Weight enabled
Spy Game - Get ?? kills with Ninja perk enabled (Ninja Pro V challenge)
Squawk Box - Call in 25 attack helicopters challenge
Straight Up - Win 30 Team Deathmatch games
Streaker - do the "fearless" challenge (kill 10 ppl without dying)
Stun Gun - kill one enemy while being stunned by a stun grenade
Submit to Authority - get killed by a riot shield
Suppressor-x amount of kills with a silnced weapon
Sureshot - Get 10 hipfire kills kills using Steady Aim
Surgical - Empty an entire assault rifle clip without missing (challenge)
TacDel - Kill 25 players that spawn using Tactical Insertion (Tactical Deletion challenge)
Take a Stab - 15 throwing knife kills(challenge)
Team Player - Win 5 Team Deathmatch Games
Tha Bomb - Kill a bomb planter 10 times
The Avenger - Avenge a fallen teammate
The Bigger They Are.. - kill the Top player 3 times in a row
The Brink - Get a 3+ kill streak when near death (when the screen is flashing red). (The Brink challenge)
The Feared - be in the top 3 plyers in 3 games
The Inciser
The Legend - be the last man in search and destroy
The Mad Bomber - plant a bomb
The Mastadon-get a flawless game(challenge)
The Watchman - Call in 100 UAV’s
Time is Money - get 5 paybacks with semtex(Bang for your Buck I challenge)
Time on Target - get 2 predators in one game
To The Extreme - Win a Team Hardcore match with the top score (MVP Team Hardcore challenge)
Toxic - be on the losing team when a tactical nuke is used
Trackstar - Sprint 52 miles with marathon
Transformer - Get the last kill in a match with a Pave Low
True Liar - Final kill with a Harrier
Unbelievable - Get the last kill of a match with a throwing knife (Unbelievable challenge)
UAV Jammer - Bring down 100 enemy killstreaks while using Cold Blooded Perk (Cold Blooded Pro V Challenge)
Unbreakable - Block 1000 bullets with the Riot Shield OR deflect10 explosions with the riot shield
Voyeur - call in 25 UAVs
Wargasm - Obtain all 3 of your selected Killstreak Rewards within 20 seconds (challenge)
Sources- http://www.game-tuts.com/community/showthread.php?t=9916
1bullet2kills - 1 collateral damage kill
1st Lt. - earned by leveling up
1st Sgt. - earned by leveling up
2fast - 15 kills with Sleight of Hand perk enabled
30 Something-30+ kill strek
Absentee Killer - Gain a game winning killcam with a sentry gun (Absentee Killer challenge)
Accident Prone - Fall 15 feet or more and survive (Base Jump challenge)
Airborne - call in 3 pav lows(challenge)
All Pro - Headshot 2+ Enemy's with a Single Sniper Bullet
All Your Base - Extreme Cruelty challenge
Angel of Death - call in 10 AC-130's (challenge)
Armed and Dangerous - complete Bling Pro VI challenge
Art of Stealth - complete 250 close range kills with the Ninja perk enabled
Backsmasher - kill someone from behind with the riot shield (Back smasher challenge)
BOOM! Headshot - 25 headshots with an LMG
Backstabber - Stab an enemy in the back with your knife (Backstabber challenge)
Big Brother-call in 100 UAV's
Bite the Bullet - Get 1000 kills using Stopping Power
Blindfire - Kill an enemy while you are still dazed by a flashbang (Blindfire challenge)
Bling Bling - Get 450 kills with Bling perk enabled (Bling V challenge)
Blood Brothers - Win 15 (core) Team Deathmatches (Operations challenge)
Blood Money - Get 5 Payback kills with headshots (Color of Money I challenge)
Blunt Trauma - 2 kills with Riot Shield
Bombshell - kill the bomb carrier (challenge)
Bow Down-Have the highest KDR at the end of a match
Broken Arrow-Have the highest KDR at the end of a match
Bullseye-get a semtex stick
Catch Shrapnel - get 5 claymore kills
Charity Case - call in 50 Care Packages, Sentry Guns or Emergency Care Packages
Chick Magnet - Call in 2 EMPs (Blackout I Challenge)
Cloak and Dagger - get 5 throwing knife kills (Carnie I challenge)
Commander - earned by leveling up
Companion Crate - call in 25 Care Packages
Completely Numb - Take enough damage to normally killl you with painkiller activated.
Concussive Barage - Finish off a kill with a stun grenade(challenge)
Counter Intelligence - get 250 kills with Scrambler perk on(challenge)
Crackin' Skulls - Get 25 headshots using an Assault gun (challenge)
DZ Clear - call in 25 care packages
Deadline - Use 100 killstreaks while using the Hardline perk (Hardline Pro Challenge V)
Devestater - kill every member of the enemy team (Tango Down challenge)
Dictator - Every bullet in an LMG clip hits an enemy (challenge)
Dishes are Done - Get an assisted suicide kill
Dish the Rock-Most assists in a game
Disruptor - get 5 kills with Scrambler perk enabled (Scrambler Pro 1 challenge)
Double Down-Get 25 kills using the Bling perk
Drifter - destroy 1 car
Drone Killer - Get a winning kill with predator missile (challenge)
End of the Line - End Game II challenge
Enemy of the State - be the last man standing and get 3 kills
Enemy with Benefits - Kill two enemies by sticking a semtex to one of them
Epic-Kill the whole enemy team within 10 seconds
Explosive Ordinance - 15 search and destroy wins (challenge)
FNG - start out with this
Flying Tank - Call in 10 pave lows (challenge)
Flyswatter - shoot down a chopper
Frag Out - get 10 grenade kills
Friends With Benefits - complete The Resourceful challenge
Full Arsenal - 15 kills with One Man Army activated
Gen. - earned by leveling up
Get Real - win 1 Hardcore Team Deathmatch (Hardcore Team Player 1 challenge)
Get to the Choppa! - Call in 3 chopper gunners (challenge)
Ghilie in the Mist - 100 One Shot Kills (2nd Ghillie in the Mist Challenge)
Ghostrider - Kill 3 enemies with a predator missile in one launch
Givin' Static - get 5 counter UAVs
Global Thermonuclear War - call in 2 a tactical nuke(tactical nuke challenge)
Godhand - call in 3 (?) AC-130s
Grassy Knoll - Get the Grassy Knoll accolade (most time spent prone)
Hair Trigger - Hair trigger accolade
Hard to Kill - get 2 kills on Last Stand
Hardcore Only - Win 10 HC TDM games
Headrush - 5 headshots with an SMG
Heartbreaker - steal x amount of enemy crates
Hello "Its Personal" - Injure an enemy with a weapon and kill him with the throwing knife
Hi Def - Get the game winning kill cam with a chopper gunner
High Caliber - Finish an entire match without dying
Highlander - Go a full length match without dying
Hijacker - Take 10 enemy care packages (Hijacker I challenge)
Hot Shot - Defuse 2 Bombs
ID Thief - get a payback kill with Copycat enabled
Impaler - get two melee kills with Commando enabled
Invincible - Regenerate from enemy damage 5 consecutive times without dying (challenge)
Invisible - Take out 3 enemy killstreak rewards while using coldblooded (challenge)
Jack-in-the-box - Kill somebody within five seconds of spawning at a tactical insertion
Joint Ops - tied to the assists challange 'Point Guard'
Jump Jet - call in 5 harrier airstrikes
Klepotomaniac - Kill 3 enemies with 3 different weapons in a single life
Live Long.. - survive for 5 minutes
Living Dead - for surviving and getting back on your feet after you've been downed to final stand
Lone Wolf - Win a free for all match (challenge)
Low Profile - get 15 prone shots (Prone I challenge)
Mach 5 - Every bullet in an SMG clip hits an enemy (Mach 5 challenge)
Maj. - earned by leveling up
Martyr - get 1 kill with martyrdom
Mastermind - 15 kills with a claymore (challenge)
Mmmm... Brains-complete the two barrels challenge
Money Shot-get 25 py back kills
My Lil' Pwny-prestige and then get 50 kill with a silnced weapon
NBK - get 3 Longshot kills in one life
New Jack - get a Payback kill with a throwing knife(ATM challenge)
Ninja - complete commando challenge V
No. - shoot enemy player as they are cooking a grenade
Noob tuber - kill an enemy with a grenade launcher without detonation (Ouch challenge)
OG - Get a game winning kill with a helicopter (challenge)
OMFG - Kill an enemy, pick up his weapon, then kill him again with his weapon (Cruelty challenge)
Omnicide - Kill the entire enemy team within 10 seconds (challenge)
Omnipotent - Have the highest K/D ratio at the end of a game 25 times
One Inch Punch - get 750 kills using Sleight of Hand
Overwatch - Call in 5 UAVs (Exposed I challenge)
Owned - Get a game winning kill with a riot shield (Humiliation challenge: Owned)
Perfectionist - for emptying a sniper clip without missing a shot (Hit an enemy with every round you fire from that clip).
Philanthropist - let 100 teamates take your care packages
Pineapple Express - get 25 grenade kills
Plane Whisperer - get 2 air strikes in one game
Plastique - get 5 kills with C4
Preemptive Strike - Complete Hardline Pro I challenge
Pro Gambler - call in 100 total airdrop crates (Airdrop Inbound II challenge)
Public Enemy - Play Team Deathmatch and get the top score overall (MVP Team Deathmatch challenge)
Pushin' Daises - fall 30 feet or more to your death (Goodbye challenge)
Pyromaniac - destroy 2 enemy equipment
Rainmaker-25 kills with the predator misille
Rain of Fire - Predator missile challenge I
Reign Down - Call in 5 attack helicopters (Attack Helicopter Veteran I challenge )
Rejected - Destroy 15 enemy equipment (challenge)
Reloaded - Use Scavenger 10 times to resupply (Scavenger I challenge)
Remote Viewer - 5 Bullet Penetration Kills
Rival - kill the same enemy 5 times in a single match
S.S.D.D. - earned by leveling up
Sgt. - earned by leveling up
Share Package - have someone on your team pick up your emergency drop
Sidekick - Kill 3 enemies with secondary weapon in 1 life
SIGINT - Call in 25 Counter UAVs (Interference 2 challenge)
Silent Strike - Complete Ninja Pro I challenge
Skeet Shooter - kill one enemy that's in mid-air (Hard Landing challenge)
Smash Hit - Get a 3 Killstreak with a riot shield
Speed Demon - run 2 miles with Light Weight enabled
Spy Game - Get ?? kills with Ninja perk enabled (Ninja Pro V challenge)
Squawk Box - Call in 25 attack helicopters challenge
Straight Up - Win 30 Team Deathmatch games
Streaker - do the "fearless" challenge (kill 10 ppl without dying)
Stun Gun - kill one enemy while being stunned by a stun grenade
Submit to Authority - get killed by a riot shield
Suppressor-x amount of kills with a silnced weapon
Sureshot - Get 10 hipfire kills kills using Steady Aim
Surgical - Empty an entire assault rifle clip without missing (challenge)
TacDel - Kill 25 players that spawn using Tactical Insertion (Tactical Deletion challenge)
Take a Stab - 15 throwing knife kills(challenge)
Team Player - Win 5 Team Deathmatch Games
Tha Bomb - Kill a bomb planter 10 times
The Avenger - Avenge a fallen teammate
The Bigger They Are.. - kill the Top player 3 times in a row
The Brink - Get a 3+ kill streak when near death (when the screen is flashing red). (The Brink challenge)
The Feared - be in the top 3 plyers in 3 games
The Inciser
The Legend - be the last man in search and destroy
The Mad Bomber - plant a bomb
The Mastadon-get a flawless game(challenge)
The Watchman - Call in 100 UAV’s
Time is Money - get 5 paybacks with semtex(Bang for your Buck I challenge)
Time on Target - get 2 predators in one game
To The Extreme - Win a Team Hardcore match with the top score (MVP Team Hardcore challenge)
Toxic - be on the losing team when a tactical nuke is used
Trackstar - Sprint 52 miles with marathon
Transformer - Get the last kill in a match with a Pave Low
True Liar - Final kill with a Harrier
Unbelievable - Get the last kill of a match with a throwing knife (Unbelievable challenge)
UAV Jammer - Bring down 100 enemy killstreaks while using Cold Blooded Perk (Cold Blooded Pro V Challenge)
Unbreakable - Block 1000 bullets with the Riot Shield OR deflect10 explosions with the riot shield
Voyeur - call in 25 UAVs
Wargasm - Obtain all 3 of your selected Killstreak Rewards within 20 seconds (challenge)
Sources- http://www.game-tuts.com/community/showthread.php?t=9916
