"Most of us have had experiences which are verging on hallucination. It shows the power of the brain to knock up illusions."

Inspired by @Tienrand's suggestion.

It does not attack your body directly; instead, it projects suffocating, hyper-realistic illusions into your consciousness to drive you to madness or fatal panic. Every terrifying sight and sound you experience right now is its doing, designed to injure your or give up the will to fight.

Watch your surroundings (or not ), don't trust anything you see (or do, trust it).