Jaws

The monster's jaws spread wide open. He closes his eyes only to deceive you—he's already been watching your every move.
Stay still now. If you move, you'll feel that unbearable tingling all over your skin. Go away, monster, you think. "Go away, monster," you whistle. "Go away, monster!" You shout. But the monster just opens his jaws more, as an educated response.
Go on now, walk past that awful, stinky mouth. It can't be that bad. People have described its insides so detailedly, it just can't be that bad.