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?