There are various collectibles players can find while exploring the open world of Zeta Halo in Halo Infinite--including the Fog Skull. As with most other Skulls, it adds a challenging modifier to the campaign difficulty. Its particular modifier disables the motion tracker, making it harder to locate enemies.
Locating the Fog Skull in Halo Infinite is required to unlock the Catacomb Achievement for finding all Skulls, and the Headmaster Achievement for completing all main missions on Legendary
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