At certain points of the game Leon and Claire are hunted by the mysterious Tyrant, or Mr. X as he's sometimes referred to. This hulking great mutant is an unstoppable force, literally, and will shrug off gunfire and explosive damage alike. So your only option is to run away, weaving in and out of rooms to get around him. But one thing the game doesn't tell you is that the Tyrant will head towards any gunfire he hears. So if you're shooting at zombies, he'll start heading in your direction. This adds an extra layer of tactics (and tension) to the game, because it's often worth just running past zombies rather than alerting the Tyrant to your current location. If you are ever cornered by him, a thrown flashbang grenade will blind him for a few precious seconds.