Separating the facehuggers from the chestbursters
There's a lot of scary monsters in movies, but none are quite so terrifying as the xenomorph. First introduced in Ridley Scott's Alien, the beast has cropped up in several sequels and spin-offs, each time making us more and more afraid to enter abandoned space stations. Or, for that matter, anywhere that's dark.
Name another creature that's biological defense system - in this case, acid for blood - can cut through the hull of a ship. Think that's cool? What about a being with mandibles that would baffle even the most experienced of dentists? It's impossible. And, while I'm loathe to quote the duplicitous wretch that is Ash, he does have a fair point: They are the perfect specimen. But did you know there's not just one type?
Xenomorph embryos adopt certain characteristics of their hosts, meaning there's a lot of variations on this ghastly theme.
This nasty little parasite is the first xenomorph to appear in Alien. It has eight finger-like legs, allowing it to scuttle very fast, and a long tail. Its birth marks the beginning of the xenomorph's life cycle. It hatches from an egg, attaches itself to the face of its host and inserts a long proboscis - a tube - down the throat, allowing it to plant an embryo in the host's chest. Nice.
To ensure that the embryo is safely nestled into its warm snuggy environment, the facehugger likes to get a good grip on things. That's why any attempts by meddling humans to remove its legs makes its tail tighten around the host's neck. Try and chop its legs off? Fine. It'll just bleed acid everywhere. Once the xenomorph embryo is secure, the facehugger drops off and dies.
Alien 3 initially had plans for a Super Facehugger, spotted in behind-the-scenes photos, that holds the embryo for an alien queen. That was scrapped, however.
Warrior / Drone
The standard xenomorph that's most recognisable has two main variations, typically referred to in fan circles as drones or warriors. They emerge first from their hosts as 'chestbursters', small worm-like beings, and grow to full size in a matter of hours.
The creature in Alien is dubbed a Drone. Designed by H.R. Giger, it has a smooth, elongated head, a vertebrate-esque body, a long, spiked tail, two sets of retractable jaws, and the ultimate weapon: acid for blood. Initially, its purpose was to create a suitable environment to house its victims so they could be turned into new eggs. Ridley Scott ended up cutting a scene which would have made that part of the beast's reproductive cycle. It shows Dallas and Brett cocooned and midway through a hideous transformation.
Luckily, that was axed, making way for the Warrior. James Cameron designed this very similar version for the sequel Aliens. It looks mostly the same, except for a slightly different ridged design on the carapace and its allegiance to the queen.
Alien queens differ from the warriors and drones, and we're not just talking size. Yes, they're massive and have huge crests perched on their heads, adding to their stature. But their purpose is mainly reproduction. They prefer a quiet life, chilling in their hives popping out hundreds of eggs from their attached ovipositors (that's the big translucent tube thing used to plop them out.)
Still, they're not averse to a punch up. The first time a queen appears onscreen is toward the end of Aliens, when Ripley discovers the nest and decides to incinerate it. The queen quickly rips away from the ovipositor (ouchie) in pursuit of Ripley and even figures out how to summon an elevator. She's really smart.
Later queens appear in Resurrection and Alien Versus Predator. The design of the AvP version underwent some tweaks, namely making her faster. It disrupts some of the menace she has in Aliens, like the moment she slowly descends from the dropship after tearing up Bishop, her toothy smile dripping with saliva. Way scarier.
Because xenomorph embryos adopt traits from the host, we get all kinds of strange variations, like the dog version in Alien 3. Also referred to by the crew as the 'bambi burster' and the 'runner' or 'dragon' by fans, it's a much smaller creature, possessing the four-leggedness and agility of a canine, along with the rest of the xenomorph's usual behaviors.
How it can crawl up and around walls like Spider-Man is presumably something that's just inherent in the xenomorph. Or perhaps the dog's granddad was a circus performer.
Due to an anomaly in how the dog DNA and xenomorph DNA meshes together, the chestburster is a lot bigger than the ones spawned from humans. Originally, the special effects crew tried attaching a xenomorph costume to a whippet for that added touch of authenticity. Yeah... that didn't really work, so they went with a CGI version instead.
Alien 3 underwent many, many changes during production. One of those alterations affected how the xenomorph makes its way onto the prison planet. As seen in the Assembly Cut, the movie opens with the prisoners using a herd of oxen to yank Ripley's EEV escape pod out of the water. Can you guess what happens next?
Yes, one of those poor creatures is attacked by a facehugger. In this longer - and greatly improved - edit of the movie, instead of seeing a chestburster emerge from a dog, we see one break out of an ox. Fans speculate that the reason the creature is so big is because it took longer to crack through the ox's chest. This is probably why the ox is dead at the time.
Alien Resurrection has Weyland-Yutani scientists cloning Ripley so they can get their greedy hands on the alien queen embryo in her chest. They succeed in harvesting the xenomorph's DNA and make a load of aliens and a load of Ripleys.
Through all the messed-up cloning stuff, the only surviving Ripley sort of becomes half-Alien and the Alien queen sort of becomes half-Ripley, complete with a human reproductive system. And you know what else the queen has? Butt-ugly offspring.
The Newborn is... man, who knows what it is. Half-human, half-Alien, 100% revolting. It bursts forth from the queen's humongous womb, takes one look at its mother and smashes her jaw clean off. Aside from its shitty attitude, it's also pretty unpleasant to look at. Its skin resembles hardened mucus. Its deep-set eyes look eerily human. To keep the whole alien-human aspect going, it originally had two sets of engorged human genitals, but they were digitally erased. All hail CGI.
Prometheus is a touchy topic among Alien fans, but it can't be denied that the creature at the end is related to the xenomorph. While there's no official name for it, it's referred to as the Deacon or Proto-xenomorph. There's no mistaking that it's some variant of the beast in the main Alien series, especially if you inspect its features. That long, domed head, the double-jaw, the general hostility immediately after being born? All xenomorphic traits.
As the film takes place years before the first Alien, it's assumed that this creature is a distant ancestor of the xenomorph. If that's the case then the xenomorphs had human DNA in them way before Alien Resurrection.
Let's break it down: Elizabeth Shaw gets impregnated by Charlie Holloway who's infected with the black goo. The resultant "offspring" is a giant starfish-shaped creature, the Trilobite, which grows at an alarming rate and later facehugs one of the Engineers. Sometime later the Deacon bursts out of the dead Engineer's chest.
It's possible that we'll see the Deacon again, but as Covenant is plotting to reintroduce the xenomorph proper into the franchise, don't count on it.
The final moments of Alien versus Predator show one of the Yautja (the official species name) carted onto a ship with a xenomorph facehugger attached. Say hello to the PredAlien.
This version is perhaps the most deadly. It incorporates the violent, unrelenting qualities of the alien with the violent, unrelenting qualities of the predator. It's a lot stronger than the human-spawned xenomorphs and boasts a number of other unique visuals. The pred's fancy dreadlocks, for instance.
Another unpleasant twist in the xenomorph life cycle is that the PredAlien removes the need for an egg-laying queen. It simply opens its hideous jaws, latches its mouth over the host/terrified victim, and chugs multiple chestburster embryos directly into the body. Except according to the film's directors, they're actually bellybursters that cause the person to split wide open from the stomach. The whole thing's made even more horrible in the sequel, when the PredAlien does that to a pregnant woman.