I have the answer, a Xenomorph Scout (Xenomorphious Scuntious) is a rare species of scout, only appering on Halloween mode. Something about Halloween Mode causes scouts to morph into the Xenomorph Scout. They use their very strong claws to cause people to bleed, and throw sharp objects as a ranged attack. They are very deadly, and are very agressive.

They are able to run at a very intense speed, and you might be horribly scratched 2-4 times before they will flee, and leave you to die.

Here is a video demenstration of a trained Xenomorph, showcasing its weakness, and its power.

For a Pyro: spray some Fire to scare them off, if they use a ranged attack, just reflect it! Simple!
For Spy, Medic, and Sniper: Run if you can.
For Engineer: Bait them to your Sentry, if you can.
For Heavy: Shoot him.
For Demo: Lay down Sticky traps and bait them towards the traps.
For Soldier: Shoot him.
For Scout: Lead him toward your team.

In conclusion a Xenomorph Scout is in no means to be made fun of, unless you want your head seperated from your body.

Hope you enjoyed this, give it a rating if you like.