Smash your opponent into something 20 times in the "Chicken Fight!" level

Complete the "Santa's Sweatshop" level

Kill Vernon

Complete the "No Cheese, Please" level

Kill 500 enemies using Stewie

Complete the "Pussy Whipped" level

Complete the "Something's Amish" level

Perform a multi-kill with a grenade

Kill an enemy with a single shot to the head

Defeat 10 enemies with a melee weapon

Destroy all of the piñatas in the "It's All Greek to Me" level

Reach Sergeant (Level 10) in multiplayer Public Match.