Some strange space debris has landed in the area!
A large space of a space shuttle will crash onto the map. Within will be a giant alien known as the queen. Which will exit accompanied by a few guards to defend it. The queen will try to move to a safe location to make a nest.
The queen lay eggs which will hatch into face huggers that will latch onto any living thing animal nearby, going quick damage. If it kills the target it will stay latches on for a moment then burst into a xenomorph (which we'll call alien hunter for copyrights sake).
If a face hugger hits the player you'll be blinded and will start taking low but rapid damage. You'll need to continually press attack to rip if off your face.
The queens goal is to make a safe nest and build a strong hive and if all goes well. Have a new queen to spread further. Her hunters will protect her, but also go out to hunt and scout out the area for threats. they also have a hive mind going on, so if the queen is in trouble all nearby xenos will be alerted and come to help her.
it's not all bad. The queen also produces a really nice Royal jelly that has really good healing properties and could be used for some high quality recipes. so if you where to say, capture one, you could make a killing. Just make sure it doesn't kill you.
But if you you don't want some jelly and just want to wipe these things out, don't worry. Fire is your friend, but if you don't have access to a flame thrower. Use music, a boom box will make it hard for the hive mind to communicate with each other, allowing you to get by without alarming the whole swarm to your location.