* Berserkers. 7 foot 3 inch-tall armour-plated monstrosities that makes a high-pitched scream as it charges; it's totally blind so it has to 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 [[spoiler: the Lambent Berserker]] in ''Gears of War 3''. Picture it, [[spoiler: you just saved Anya and Sam from being overrun by Lambent Locusts. As you make your way back to the fort, you see a rather large Lambent stalk appear in front of you. Then, it pops out screaming and instantly killing the COG in front of it before tossing the jeep in your direction. Surely the Hammer of Dawn can kill this thing right? So you make your way back inside the fort and watch it get nuked via satellite, only to find out that it survived. And is ''very'' pissed off.]]
** By far the worst thing about the Berserker though, is that the Locust actually ''reproduce by raping them!''
*** No, the worst thing is that raping them is ''necessary'', because they really are just mindless killing machines. They have to be tied down in order to actually breed. Any Locust that got close to one otherwise would only get ripped apart.
** Oh, and the way you're introduced to them? One of your random AI partners completely loses his shit, says "ScrewThisImOuttaHere" and runs into a convenient hallway, only to get pounced upon by the Berserker and '''eaten alive'''. All that remains of him when you go into the hallway is a bloody mass of leftover flesh and bones. The scene in question is effective enough that it's one of the rare occasions on which the spilling of way more blood than could possibly fit in a human body is [[AvertedTrope not in any way]] [[{{Narm}} narmful]].
* [[DemonicSpiders The Kryll]]. [[DarknessEqualsDeath 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 ''Franchise/ResidentEvil''. 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.
-->'''Niles:''' "I would begin exiting the facility if I were you."
* The first time you meet [[spoiler: Lambent Humans]] 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. [[spoiler:Marcus reaches out to touch her, and the woman whips around to face him, and in that instant we see that not only is her flesh practically liquefying, but that horrible [[SicklyGreenGlow lambent light]] is shining out of her mouth and the gaping holes where her eyes should be. And she screams as she rushes at you]]. Anya shouts that [[spoiler:the woman isn't human anymore]] 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 [[spoiler:ZombieApocalypse]] 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.
** The [[spoiler: Lambant Humans]] shows up again with the same creepy suspense and tension in ''Aftermath''. Especially unnerving when you hear them whisper ''die!''.
*** Sometimes they scream "[[AFateWorseThanDeath Kill me]]!"
* Leviathans, and not just the Lambent ones either. Imagine the shark from ''Film/{{Jaws}}'', but three times bigger with massive teeth. Leviathans also have pretty creepy eyes, either the pure blue ''Vampyroteuthis'' [[http://scienceblogs.com/pharyngula/wp-content/blogs.dir/470/files/2012/04/i-6ccf90c0455b735133f92f0aa1685bc4-vamp_open.jpg eyes]], or the Lambent Leviathan's GlowingEyesOfDoom.
* The final boss of ''Gears of War 2''. [[spoiler:A Brumak gets overdosed on Imulsion and when it mutates its head violently deforms, with a second head bursting from its mouth, which is followed by the creature going berserk and growing tentacles from its body.]]
* It doubles as a TearJerker, but imagine being in Dom's place for a second. His life is made of AdultFear. His ''entire'' family is dead, and the only part of it that could still be alive is his wife, the only woman in his life he's ''ever'' loved up to that point. She is [[DistressedDamsel missing]], possibly [[NeverFoundTheBody dead]], and he's been on a crusade to find her, or at least her fate, for years. And then in ''2,'' he finds out that the Locust have [[POWCamp taken prisoners]], which they [[LeaveNoSurvivors never do]], and via [[DrivenToSuicide Tai]], he finds out ''[[ColdBloodedTorture why.]]'' None of this points to a happy ending, but he keeps up [[HopeSpot hope]] despite that. And then he finds her. His [[DownerEnding wife]] has been [[spoiler: lobotomized, malnourished, and tortured into insanity, and she's been like this for]] ''[[spoiler: years.]]'' [[spoiler: The damage is clearly irreparable, and Dom has to MercyKill her.]] Dom is ''broken'' after this. DespairEventHorizon doesn't even begin to describe what happens to him.
* ''Raam's Shadow.'' Right before a child is about to evacuate Ilima City on an APC full of civilians, Tai gives him encouraging words to help him survive the days to come. A cute, hopeful moment [[spoiler: that is brutally cut short. Not thirty seconds later he and you are forced to watch as that APC and everyone in it is pulled underground by a Corpser, spelling certain death for said child.]]