Gears of War/Nightmare Fuel

"Niles: "I would begin exiting the facility if I were you.""
 * Berserkers. A 12 foot armour plated killing machine that makes a high pitched scream as it charges? And its totally blind so it has to smegging sniff you out? And sometimes you have to lure it towards you by shooting it, and watching the bullets bounce off, only for it to shriek towards you once more, and then diving just out of the way so she (yes, she) smashes a door down or something. Then you have to run past her through a tiny gap, while she flails wildly in all directions.
 * You think the NORMAL Berserkers are bad, wait until you see  in Gears of War 3. Picture it,   Oh Crap indeed.
 * The Kryll. Don't leave the light.
 * Gears 2 has the New Hope Outpost. It can be...jarring, to say the least, to be playing Gears of War and suddenly walk right into something out of Resident Evil. The old, decaying research facility is creepy enough, but then you reach the basement, and there are things in giant stasis tubes, and when you throw a lever to access the facility's computer, it trips some sort of failsafe on the tubes, and they start waking up...


 * The first time you meet  in Gears of War 3. Marcus and Anya are in the sewers under the town of Mercy, and they spot a woman huddling in a corner, crying for some reason. They get closer, and Marcus asks if the woman's okay, and every viewer knows damn well what's about to happen, but somehow it's still chilling. . Anya shouts that  and that Marcus should just open fire, but most players won't need any encouragement to gun that thing down.
 * The entire lead-up to that moment is more and more unnerving. Marcus, Dom and Company are clueless about what's going on, but to most every viewer, the signs of the will be all too clear: the seemingly abandoned town, the crazed survivor shouting about some kind of disease, the locked doors with giant red X's painted on them, and the fact that those doors are barricaded from the outside...
 * Leviathans, and not just the Lambent ones either. Imagine the shark from Jaws, but 3 times bigger with massive teeth.
 * Leviathans also have pretty creepy eyes, either the pure blue Vampyroteuthis eyes, or the Lambent Leviathan's Glowing Eyes of Doom.
 * The final boss of Gears of War 2.
 * The New Hope Outpost in Gears of War 2 has a pretty twisted history. Some of it is trying to kill you. Then there's . Oh, and don't forget the Sires.
 * Fighting a Brumak in Horde. Alone. Without help!
 * The Heart Leeches in the comics.