|Marcus has a rough night ahead of him.|
The Kryll are essentially bats from hell. They lived primarily underground before the chaotic events of Emergence Day (when the Locust emerged from their underground habitat to begin a siege on the surface of the planet). Because they are accustomed to dark underground caverns, Kryll cannot tolerate light at all. In the game we see that light has varying effects on these creatures, such as making them feel pain, or flat out causing them to burn to a crisp. Therefore these enemies only emerge from underground at nighttime, and hunt in groups containing millions of Kryll.
|Kryll filling the skies.|
What makes Kryll dangerous is their carnivorous nature. If they catch any living being standing exposed in the dark, they will swoop down in small (well if you call "hundreds" small) groups and devour it. During the inevitable night missions in Gears of War, we witness Kryll reducing human beings to nothing but a bloody stain in mere seconds.
|Using a UV cannon to neutralize glow-eyed Kryll.|
During these night missions, you absolutely have to stay in lit up areas if you want to survive. There are quite a few thrilling segments where you have to charge from streetlight to streetlight, occasionally diving into a well-lit building, all while taking heavy fire from Locust armies. If you stay outside the light for too long, you're rewarded with a brutal scene of protagonist Marcus Fenix being eaten alive.
You will encounter just a few of these enemies in the game, but the battles are definitely worth waiting for. Berserkers are female Locust, and just like a Black Widow spider, the females are larger and much more dangerous than the males.
Berserkers for some reason are blind, and therefore rely on sound and smell to locate prey. Your first encounter with this monster in Gears is inside a tomb, where a Berserker has gotten loose and proceeds to hunt you down. As you creep through the halls you won't see her, but you'll hear her growling and smashing objects as she tries to locate you. Before you know it, the Berserker smashes through a wall directly in front of you, and commences her charging attack.
|This is not good...|
This is an especially intense moment of the game, because the goal of the battle is to lure the Berserker out of the tomb so you can hit her with a satellite-based laser (she will shrug off your bullets as if they were spitballs). Naturally you just want to run away from this huge, ugly creature, but since that's not an option you have to choose carefully when to get her attention so she will charge in the direction you choose. Get too close to her and you'll get to see Marcus Fenix mauled to death. This is a battle you'll have to experience yourself in order to feel the fear of being in close quarters with an almost-unstoppable enemy pursuing you.
In conclusion, I find these two enemy types to be the most frightening in the series, and I'm still disappointed that they didn't make any appearances in Gears of War 2 or 3. They helped add variety to the battles and are sorely missed. Did you guys play Gears of War 1? If so, did you find Kryll and Berserkers to be pretty intense enemies?