Big Head: In Horde Mode, unlock the Gold Horder medal. Unlock this medal by completeing 1,000 waves.
Pinata: In Beast Mode, unlock the Gold Investor medal. Unlock this medal by collecting 500,000 tokens.
Headless Chicken: Available at start.
Laugh Track: Unlock the Bronze Tour of Duty, For the Horde, I’m a Beast, and Warmonger medals. Unlock Tour of Duty by completing the Campaign mode on casual. Unlock For the Horde by completing all 50 waves on casual. Unlock I’m a Beast by completing every wave without failing on casual. Unlock Warmonger by completing Arcade mode on casual.
Flower Blood: In Arcade Mode, unlock the Silver King of Cog medal. To unlock this medal, earn 2 million points in Arcade Mode.
Comet: In Versus Mode, unlock the Gold Shock Trooper medal. Unlock the First Blood ribbon 1,000 times. To unlock the First Blood ribbon, get the first kill in a round.
No Ammo Pick-ups: Available at start.
Super Reload:In Versus Mode, unlock the Bronze Master at Arms medal. Unlock this medal by scoring 100 kills with all five of the starting primary and secondary weapons.
Infinite Ammo: In Horde Mode, unlock the Combat Engineer ribbon 100 times. During a round build, repair, or upgrade five fortifications to unlock this ribbon.
Enemy Regeneration: In Arcade Mode, unlock the Silver Afficianado medal. To unlock this medal, play 150 chapters in Arcade mode.
Vampire: In Versus Mode, unlock the Executioner ribbon 100 times. To unlock this ribbon, score the most executions in a round online.
Instagib Melee: In Beast Mode, play as a Wretch and score 200 kills.
Big Explosions: In any mode, unlock the Hail Mary ribbon 100 times. To unlock this ribbon, use the Boomshot and score kills from over 200ft.
Must Active Reload: Unlock the Silver Active Reloader medal. To get this medal, perform 2,500 perfect reloads.
Friendly Fire: In Co-op Campaign, complete the co-op campaign with four players.