After looking thinking about the Raven i realized something. The Raven has a very large resemblance to a Palatine. Is it possibe that it could be one?
I was just thinking the other day regarding the Raven, - given that with Alien: Isolation xenomorph drones with visible skulls beneath their domes are cannonical rather than merely a design change, and given the same fact not just with drones but also some warriors in Aliens: Colonial Marines, I was wondering whether such creatures are in fact a varient of xenomorph who, given enough time, will evolve into ravens, - the basis of my idea is that the 'warrior' is not the final stage of the creature and further evolution is possible. Some people have suggested that the Raven is the xenomorph from the pilot, - given the evolution theory this is supported, and perhaps the alien was hibernating in the ship, and with the birth of the queens, it heard the psychic call of the queen and came to the colony? With this in mind, perhaps the host-adaptive nature of the xenomorphs is an early-stage thing prior to them evolving into their final forms? They adopt traits in an interim stage before their ultimate stage? With Alien: Covenant lined up for next year, (can't wait!) and further Alien films, perhaps this will be revealed.