Complete mission "Blood Drive".

Down yourself by grenade or explosion.

Unlock 10 Character Heads or Skins.

Complete mission "Beneath the Meridian".

Complete 20 Side Missions.

Complete mission "Atlas, At Last".

Complete mission "Hostile Takeover".

Reach level 10.

Kill an enemy with an exploding barrel.

Complete the mission "Shoot This Guy in the Face".

Show thine worst enemy, the abomination known as "The Darkness", who is the nerdiest of them all.

Purchase 5 items from the Black Market.