[@EWillden]
It's been a while since I've seen the movies but I've seen all of Alien Isolation so I know they are very hard to kill as their blood is acidic, they have a hive mind controlled by a Queen, they are born from a individual being incubated by a face-hugger then burst from the beings chest. They grow quickly after birth, they have an inner mouth and their tail can be used as a spear.

If I am completely wrong, please let me, I'm just going off of what I saw in Isolation.