Gravemind (level)

On Gravemind (level),there is a crocodile's face you can see.

To find it,start the level Gravemind on any difficulty and go through the level as you normally would,but when you get outside the second time (not where the Angry Skull is),kill the Brute,the Jackal and the Elite and go to where the Jackal was sniping (before you killed him) and turn around.On the wall beside the door where you came out of,is a crocodile's face with something in its mouth.

If you can't see it,look on the wall for an eye of some sort,then you're looking in the right place.