Halo 2 Easter Egg - Armory Skull

Difficulty: Legendary
Level: Armory
Effect: Makes enemies know where you are, even when you are invisible

Location: After you have had your armour charged and Johnson enters and wants you in the lift wait until he says "Would it help if i said please" and then enter the elevator. He will say several other humerous thtings before he says the "codeword". After the lift stops enter the cart thing and look to right side (assuming that the right is the right of the edirection you are currently moving). Somewhere down the line there are boxes and on them is a skull, to pick it up hold down the X button.

I advise you keep the skull because it does extra damage in combat.