Complete 20 Side Missions.

Kill an enemy with an exploding barrel.

Win a round of Arms Race.

Complete mission "Divine Retribution".

Obtain all Vault Rewards.

Complete mission "The Great Vault".

Equip purple-rarity gear or better in every slot.

Earn a Loyalty Package from each weapon manufacturer.

Complete mission "Beneath the Meridian".

Kill two or more enemies with a single sticky grenade.

Reach level 25.

Tip Moxxi.