- "Get away from her, you bitch!"
- ―Ellen Ripley
The Queen is one of the large forms of the species Xenomorph XX121 that serves as the mother and leader of a Xenomorph Hive. Queens are one of the largest, strongest, and most intelligent Xenomorph castes, and their appearance differs from that of smaller variants, with a pair of extra arms growing from their chest and a large head crest extending rearwards from their skull.
The Queens are capable of engaging in combat and are formidable opponents, but such an event is a rare occurrence. Rather, Queens usually act as stationary Egg-layers within the Hive, tended to by Workers, and letting the Praetorians or Drones perform any defensive or offensive tasks. A Queen additionally oversees the maintenance of the nest, carried out again by the Workers (and to some extent, Drones). When laying Eggs, a Queen possesses a huge ovipositor that renders it immobile. Queens are significantly more intelligent than most normal Xenomorphs, displaying traits of wrath and vengeance beyond any purely instinctual behavior, have displayed problem-solving skills, and are also capable of issuing orders or commands to subservient castes.
Out of all the Xenomorph castes, the Queen possesses the most physical differences. Its most prominent feature is its immense size, typically standing around 4.5 meters in height, double the height of most other Xenomorphs, while some older Queens have been known to grow larger still. Correspondingly, many typical Xenomorph features are also considerably larger on a Queen, including her jaws, which are filled with razor-sharp transparent teeth several centimeters long, and her inner jaw, the maw of which can be almost as large as a human head.

A colorized version of a queen from Dark Horse Presents #34. Color reconstruction by Incolor.
Queens have large, armored, crown-like carapaces on their heads, into which they are able to withdraw their face and mouth as a means of protection, similar to how a turtle can withdraw its head into its shell. This great carapace is of disproportional size when compared to the rest of the Queen's very large body, and is thought to serve as a form of sensory "antenna", allowing the Queen to detect thermal, biochemical and bioelectric signals with great sensitivity. Queens also have double-jointed hind legs, two sets of dorsal tubes, which are more spike-like than on other Xenomorphs, six digit hands — with the third finger being much longer than the others — and an extra armored shell on their chest in the form of another carapace. In fact, a Queen's outer mesoskeleton is so resilient it is even capable of repelling sustained automatic gunfire, although it remains vulnerable to armor-piercing ammunition.
In addition to their two primary limbs, Queens also possess a second, much smaller pair of arms extending ventrally from the center of their chest; the exact purpose of these arms is not known. A Queen's tail is extremely long and segmented, with a large, blade-like tip. As with typical Drones, Queen tend to be black or black-blue in coloration. Egg-laying Queens are easily identified by their enormous ovipositor, which extends from beneath their tail and can be up to 9 or 12 meters in length. These ovipositors are typically suspended from the ceiling of the Hive by "straps" created from the same secreted resin as the Hive itself. Owing to the size and weight of this sac, any Queen in the laying stage is immobile and totally dependent on her subordinates for assistance and protection. However, the ovipositor can be detached in a critical situation to allow the Queen to escape, although this process is apparently painful for the Queen and it is unlikely the sac can be reattached as easily, if at all. However, Queens are capable of growing a new ovipositor within a reasonably short period of time, though this too can prove painful for them. While immobilized, the Queen typically folds her legs up under her body and is instead supported by a biomechanical "throne". When laying, a Queen will typically produce up to fifteen eggs per hour.
A Queen, despite her size ratio compared to other Xenomorphs, can sustain near-limitless gunfire before having to retreat, thanks largely to her thickened mesoskeleton and additional armor. They have also been seen to survive being almost totally enveloped by fire, although prolonged exposure to heat and flame is eventually fatal. As a result of their resilience, once released from her laying stage a Queen can destroy most prey within seconds. It has also been noted that Queens display numerous signs of extreme muscle density; indeed, Queens are capable of tearing synthetics in two with just their hands. This, coupled with their great size, makes any form of hand-to-hand fighting an unwise tactic when confronting one, even for a Yautja. The Queen is fast considering her size — specimens have been clocked running at speeds of up to 40 km per hour. They are also incredibly long-lived, with some specimens estimated to have survived for tens of thousands of years. At least in very cold conditions, Queens are apparently able to "hibernate" or otherwise suspend their metabolism as a means to further extend their lifespan.
While Xenomorphs are usually said to be asexual, Queens are typically classified as female, owing to their similarities with similar female egg-laying castes in the insect kingdom. Usually, there is only a single Queen present in any Xenomorph populace. However, on occasion it is possible for multiple Queens to come into contact with each other. Such a course of events will lead to conflict, with the ultimately dominant Queen often being referred to as an Empress and ruling over any other Queens situated in her domain.
As with the Spitter and Runner castes, Queens are capable of spitting acid from their mouths.