Well right now there are no marines to kill ANY of them, so who cares? We'd be needing other lines anyway at this point.
Problem with the Queen and Raven is you really need the power loader to kill them or some type of mech. Crusher has a tough head but soft body so it bleeds therefore it can be killed. Raven and the Queen have bulletproof exteriors so unless we get something to kill it with what is the point!? They can just run free and do as they please. Boiler is just a kamikaze fighter. They blow up and bleed acid on everyone.
Good source of info for the Alien ig'nant like myself.
Xenopedia - The Alien vs. Predator Wiki
We could make an Alien based off him. We shall call it the Dribbler.