Xeno 771 is the designation given to the cloak wearing aliens. Right now little to nothing is known about them. They seem to dissipate when struck with bullet or blade into a shower of black sparks and they leave nothing but dust behind. They have fired at our Marines and can use something akin to telekinetic powers. Right now they appear to be the puppet masters of whatever the hell is going on. We do have first hand accounts of them cloning humans from organs and first hand accounts of people working with them.
We could not understand their language despite the fact the other humans seemed to be able to communicate with them. Right now they are considered very dangerous and engage only if necessary. However we are not sure as to how much of a threat they are as it seems they have no defense against bullets or knives. They do appear to have a fear of energy weapons as they use energy damping fields to restrict their use.