Halo: Combat Evolved Anniversary skulls

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.

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 infinite ammunition.

Boom skull
Once the skull is activated, explosion radius will increase two-fold.

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-order the game.

Iron Skull
Nothing is known of this skull except for its existence in the game. It will most likely have the same effect with the Iron Skull in Halo 3 and will restart the level if a player is killed, or restart a checkpoint if multiple players are playing co-operatively.

Malfunction skull
Once the skull is activated, one random part of the HUD will disappear at every respawn.

Grunt Birthday skull
Once the skull is activated, the Unggoy's heads will explode in a shower of confetti with a headshot.

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.