Did you know that there was a giant skull in the middle of the Ark on the last mission of Halo 3? Go ahead, load up the level at rally point Alpha and look up at the sky. You might have to get to the warthog run part to clearly see it, but there is in fact a giant skull in the middle of the Ark. I found this a long time ago back in my Halo 3 days, but I never heard about it from anyone else. I would simply post a picture but ya know, there aren't any. No wait, found one!