Meet Monsters

By Matthew Hardcastle
BU News Service

The character of the movie monster likely has its origins in our collective psyche, but in bringing their personal visions of horror to life, filmmakers often root themselves in  the world of biological possibility. Here are three monsters whose terror derives in part from their parallels in the real animal kingdom.


CrawlersThe Descent

© Celador Films
Crawler, © Celador Films

The Descent (2005) stars a group of women alone in the dark, lost in an uncharted cave system inhabited by subterranean humanoids called Crawlers. These creatures seem to be an undiscovered branch of humans perfectly adapted to living in the pitch black. Exclusively cave-dwelling animals are called troglofauna, and although no known mammals have become troglofauna, the Crawlers share some of the commonest adaptations for a life of perpetual spelunking.

Lack of pigment – pale or translucent skin is a common adaptation for troglofauna, who require no protection from the sun’s rays.

Blindness – when it comes to evolution, it’s often “use it or lose it.” Without a speck of light to see, Crawlers are better off not wasting scarce cave resources developing eye sight.

Reduced metabolism – although the Crawlers seem to have quite an appetite for human flesh, they can probably go a long time between meals.

Acute Hearing – Sound is a lot more important than sight in a cave environment, and Crawlers have adapted bat-like external ears for increased reception.

Heightened sense of smell – This trait is a bit more problematic. Although cave dwellers tend to develop their non-visual systems, no primate or human species has ever hunted by scent.


Xenomorphs Alien series

Xenomorph warrior, © 20th Century Fox
Xenomorph warrior, © 20th Century Fox

The seminal sci-fi masterpiece Alien (1979) introduced the world to xenomorphs, and subsequent films in the franchise have expanded on their life cycle and biology. Although they are totally alien life forms, their anatomy does have some counterparts on Earth. Some eels possess a secondary set of jaws within their mouths and some insects can spray acid. Xenomorphs most resemble arthropods, which once grew to fantastic sizes back when the Earth’s atmosphere had more oxygen — not unlike the oxygenated environment of a spaceship.

Xenomorph facehugger, © 20th Century Fox
Xenomorph facehugger, © 20th Century Fox

The xenomorph lifecycle also has terrestrial parallels. Their colonies are eusocial like an ant colony, with one fertile queen and physically-differentiated castes. They have a complex life cycle, involving an endoparasitic phase. Facehuggers hatch from eggs laid by a queen and act as mobile ovipositors, traumatically inserting larvae into a host, much like a parasitic wasp laying its eggs inside of a living caterpillar. Unlike most earthly endoparasites, facehuggers don’t seem picky about their hosts, and their larvae can adopt genes from their temporary incubators. After incubation, the developed larvae fatally escapes its host and rapidly grows into a warrior, shedding its outer shell as needed, much like many arthropods.



Dren, © Dark Castle Entertainment
Dren, © Dark Castle Entertainment

Splice (2009) is a surreal film about the possibilities of genetic engineering. Because the modern day Dr. Frankensteins are working with a mystery grab bag of human and animal genes, a healthy suspension of disbelief makes any combination of traits plausible. As an adult, Dren is definitively mammalian (possessing breasts) so we’ll try to stick close to that Order as much as possible.

Young Dren, © Dark Castle Entertainment
Young Dren, © Dark Castle Entertainment

Newborn – Mammals like humans, cats, and dogs give birth to young that are altricial, meaning they still possess some fetal traits. Young Dren possesses a dramatic form of this in her cleft face and undeveloped arms. However she also is extremely mobile, like the precocial newborns of horses and cows.

Adult – As an adult, Dren’s most prominent feature is her tail and long hind limbs. Besides this, she is more or less externally human. Her tail is counterbalancing like a kangaroos and prehensile like a monkeys. It also has a stringer. Though this is perhaps meant to be insectoid, male platypuses do possess poisonous barbs on their hind limbs.

Other traits – without getting into too many spoilers, Dren develops more exotic traits through the course of the film. She eventually sprouts feathers on her arms and uses them like wings. This is largely for dramatic effect, resting on shaky biological ground. Dren’s species also exhibits sequential hermaphroditism, changing from one sex to another. Although in Splice this plays out more like a Greek tragedy, many fish and gastropod species are capable of swapping sexes during their lifetime.