Changed your Spartan's look in the Customize menu.
Got at least one kill with every available weapon and grenade on the Banished ship.
Killed one Chieftain and used his turret to kill another in the Repository.
Killed three enemies with the ball in an Oddball game in a matchmade game.
Killed 5 enemies with a Sniper Rifle from a vehicle. All players aboard vehicle share progress.
Killed 5 enemies with a Gravity Hammer from a vehicle. All players aboard vehicle share progress.
In co-op, destroyed all cooling towers at the Dig Site within 60 seconds of each other.
In co-op, destroyed four Fuel Silos within five seconds at either Ransom Keep or the Forge of Teash.
In co-op, lowered all three gates within 15 seconds of each other at Riven Gate.