Borderlands 2 Cheats

Phased and Confused (20 points): Phaselocked 100 enemies.
So Much Blood! (20 points): Gunzerked continuously for 90 seconds.
Cute Loot (15 points): Killed a Chubby.
Tribute To A Vault Hunter (15 points): Got an item from Michael Mamaril.
Definitely An Italian Plumber (15 points): Killed Donkey Mong.
High-Flying Hurler (10 points): Killed a flying enemy with a thrown Tediore weapon.
Token Gesture (20 points): Redeemed 25 tokens.
Unseen Predator (20 points): Remained in Zero's Deception mode for ten seconds straight.
Build Buster (20 points): Killed a Constructor without it ever building another bot.
How Do I Look? (25 points): Unlocked 10 customization items.
Friendship Rules (10 points): Revived someone from "Fight for Your Life!" that is on your friends list.
Better Than Money (15 points): Purchased 5 items from the black market.
Up High, Down Low (15 points): Gave Claptrap a high five.
Bounty Hunter (25 points): Completed 20 side missions.
Did It All (40 points): Completed all side missions.

Additionally there are twenty secret achievements.

First One's Free (10 points): Completed the mission "My First Gun".
Dragon Slayer (20 points): Completed the mission "Best Minion Ever".
A Road Less Traveled (20 points): Completed the mission "The Road To Sanctuary".
New In Town (20 points): Completed the mission "Plan B".
An Old Flame (20 points): Completed the mission "Hunting The Firehawk".
No Man Left Behind (20 points): Completed the mission "A Dam Fine Rescue".
Wilhelm Screamed (20 points): Completed the mission "A Train To Catch".
Sky's The Limit (20 points): Completed the mission "Rising Action".
Can See My House From Here (20 points): Completed the mission "Bright Lights, Flying City".
Farewell, Old Girl (20 points): Completed the mission "Wildlife Preservation".
Got The Band Back Together (20 points): Completed the mission "The Once and Future Slab".
Identity Theft (20 points): Completed the mission "The Man Who Would Be Jack".
An Angel's Wish (25 points): Completed the mission "Where Angels Fear To Tread".
Bombs Away (20 points): Completed the mission "Toil And Trouble".
Knowing Is Half The Battle (20 points): Completed the mission "Data Mining".
Cool Story, Bro (30 points): Defeated Jack.
What does it mean? (15 points): I can't even capture it on my camera.
Well That Was Easy (10 points): Completed the mission "Shoot This Guy in the Face".
Thresher Thrashed (30 points): Defeated Terramorphous the Invincible.
Feels Like The First Time (10 points): Opened the chest at the bus stop in Fyrestone.True Vault Hunter Mode
Complete Normal difficulty story mode.

DLC: Captain Scarlett and her Pirate's Booty
Complete each achievement to get the allotted gamerscore.
Completionist (25): Complete all Pirate's Booty side missions
Gadabout (25): Discover all named locations in Oasis and the surrounding Pirate's Booty zones
Treasure Hunter (75): Complete the mission "X Marks the Spot"

Minecraft enemies and outfit
In the Caustic Caverns underneath Sanctuary, near the furthest edge, there is a shallow incline. If you go along the left-most cliff beside the incline, you will find Minecraft blocks. Breaking them will lead into an area with creepers from the Minecraft games, a golden ore block with a normal outfit, and a special outfit for defeating the creepers.

Carry one more item in your backpack
You must have 2 class mods for this to work. Once your backpack is full, switch your currently equipped class mod for another one in your backpack (you can then re-equip your original class mod after you've done this). Then exit the backpack menu and you can now pick up one more item and have a backpack with 28 items in it instead of maximum 27.