Along the way you spotted cracks you could use to conceal yourself. One on the left, and one on the right. You don't have a lot of time and need to hide yourself quickly. Quietly, you backpedal to the cracks and look at them. Either one is sufficient to you hide you as it approaches, but there's a good chance it will spot you as its passes, so you'll only get one shot. You stand for a moment, facing the oncoming beast.