This skull which disables the players radar can be located in "Assault on the control room" and requires a grenade jump (throwing at your feet , jump and the force of it makes you jump higher), after going down the first elevator, there will be a transparent object in the middle of the room with fog going through it and 4 platforms around it. You need to grenade jump onto a specific platform. Its the one that looks different front the other 3, and grenade jump onto it by first climbing onto the ledge behind it then throwing a grenade right at your feet. Once onto the platform you need to jump into the vent on top of the fog platform, the skull is located right inside here.
|Unlockable:||How to unlock:|
|Fog Skull||Assault on the control room, center of the room with the fog after coming down the elevator|