Here is the full list of all 30 Tiny Tina's Assault on Dragon Keep: A Wonderlands One-shot Adventure achievements.
Remained in Zero's Deception mode for ten seconds straight
Killed 100 enemies with Deathtrap
Killed 100 enemies while using Buzzaxe Rampage
Phaselocked 100 enemies
Completed level 1 of all challenges with a single character
Had Purple-rated gear or better equipped in every slot
Revived someone from "Fight for Your Life!" that is on your friends list
Killed 100 enemies with the Sabre turret
Killed a Chubby
Reached level 35
Showed thine worst enemy, the abomination known as "The Darkness", who is the nerdiest of them all
Reached level 25
Completed all side missions
Demonstrated your skill, or lack thereof, at rolling the magical treasure orb of many sides
Vanquished the Ancient Dragons of Destruction
Won the most challenging round in Murderlin's Temple
Gunzerked continuously for 90 seconds
Fed thy noble queen 3 times during one visit to her quarters
Completed thy quest by rescuing yonder queen
Wielded the Mysterious Amulet
Completed the mission "Shoot This Guy in the Face"
Redeemed 25 tokens
Unlocked 10 customization items
Used the Lootapult to cause a Lootsplosion
Reached level 10
Purchased 5 items from the black market
Unsheathed 5 swords from Immortal Skeletaurs without leaving the area
Introduced thyself to the White Knight
Reached level 5
Slew Mister Boney Pants Guy