Halo: Combat Evolved Anniversary skulls
From Halopedia, the Halo wiki
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 levels to gain access to them.[1] The effects will not be visible in Classic Mode.
List of skulls
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.[2]
Malfunction skull
Once the skull is activated, one random part of the HUD will disappear at every respawn. [1]
Grunt Birthday skull
Once the skull is activated, the Unggoy's heads will explode in a shower of confetti with a headshot.[1]
Boom skull
Once the skull is activated, explosion radius will increase two-fold.[1]
