The Halo: Combat Evolved Anniversary Skulls are game modifiers that will be featured in Halo: Combat Evolved Anniversary with the appearance of a human skull. Like in Halo 3, they must be hunted down within the campaign levels to gain access to them. The skulls and the effects will not be visible in Classic mode.[1]
List of skulls
Bandana skull
When activated, this skull give players unlimited ammo. The skull's name is a reference to the Metal Gear franchise, in which every game has an unlockable bandana that grants the player infinite ammunition.[1]
Boom skull
Once the skull has been activated, all explosions' radius will increase two-fold.[1]
Famine skull
Once the skull has been activated, weapons dropped by the AI - ally or enemy - would have half the ammunition they normally would.[2]
Fog skull
Once the skull has been activated, the player's motion sensor will be disabled.[2]
Grunt Birthday skull
Once the skull has been activated, the Unggoy's heads will explode in a shower of confetti with a headshot.[1]
Grunt Funeral skull
Once the skull has been activated, every Grunt's methane tank will explode similar to a plasma grenade when killed. This skull will only be available to those who pre-ordered the game.[3]
Iron skull
When activated, this skull will restart the level if the player is killed, or reload the last checkpoint if multiple players are playing co-operatively.[2]
Malfunction skull
Once the skull is activated, one random part of the Heads-up display will disappear after every respawn.[2]
Recession skull
When activated, every shot the player fires would deplete two rounds instead of one. For plasma-based weapons, the depletion rate is doubled.[1]