Have you ever noticed that extra-terrestrials in most “aliens-make-contact” science fiction usually resemble octopuses, squids, or other cephalopods? At least, when they don’t just look like humans in Halloween masks or cheap make up. Arrival, Independence Day, War of the Worlds, The Simpsons… the list goes on. The default non-humanoid aliens seem to always have bulbous heads, tentacles, and slimy skin.

Some science fiction writers and filmmakers have branched out, making arthropod (bug-like) or reptilian aliens like those in Men in Black, District 9, or Alien, or even more difficult to categorise ones like the hairless, sloth-like extra-terrestrial in ET, but cephalopods still seem to be the go-to for most storytellers. You might wonder why we don’t see other interesting types of aliens more often. However, when you take a closer look, there are several good reasons storytellers keep returning to these deep-sea creatures for inspiration.

INTELLIGENCE

Unless they accidentally hitch a ride on a comet, aliens capable of travelling to earth have to be intelligent enough to develop advanced space travel. There are plenty of animals that have exhibited above-average intelligence on earth, but octopuses are usually cited as the most intelligent invertebrate, and have a large, dramatically different nervous system to humans.

Why is that significant? Despite their very different physical and neurological make up, octopuses still exhibit complex behaviours, elaborate problem-solving skills and the capacity to learn. They display intelligence, and yet we know it must be a very different intelligence or form of ‘thinking’ to our own. They also have bulbous heads, so we even have a visual shape that suggests a large brain.

All of that is to say, when we imagine vastly different, intelligent aliens, this is perhaps the best local example we’ve got to run with.

DEXTERITY

We credit so much of our technological progress as human beings to our intelligence that we often forget the role our dexterity has played in that success. However, it is arguably one of the most important traits for an advanced species to have. Just take a look at some other species we consider intelligent – dolphins, ravens, parrots, pigs and elephants. Now imagine them building complex tools, computers, or space ships and you see the problem. Until one of these creatures develops something akin to our human hands and opposable thumbs, they won’t be mining, engineering or constructing much of anything.

A cephalopod, however, is easier to picture behind the controls of a space ship, and for good reason. Octopuses have eight prehensile arms (capable of grabbing and gripping), and according to a 2015 study, those dexterous arms are “lined with hundreds of suckers that function as specialized tactile and chemosensory organs” – in other words, it seems they can touch and taste with those arms. An octopus’s arms contain two-thirds of the neurons in its body, allowing its limbs to act or ‘think’ independently. Thus tentacled creatures might not only be dexterous, but their limbs could provide them advantages we don’t have. No wonder cephalopod aliens are the preferred option after hominid ones.

SPECIAL SKILLS

Then there’s the fact that cephalopods possess a number of skills and attributes we lack, many of which can seem magical, alien or impossible to us:

– Incredibly sophisticated adaptive colouration system (if you’ve never seen octopuses or other cephalopods camouflaging, check this out!)

– Limbs that regenerate when severed

– Blue blood (copper-based rather than iron-based)

– Three hearts

– Ink they expel to blind and confuse the senses of predators

– Paralysing poison they inject into prey

– Eyes with rectangular pupils that are good at seeing in the dark

– The ability to squeeze into incredibly small spaces

All of these emphasise their difference to humans and provide inspiration for creepy alien traits. The recent film Arrival, for example, made use of ink expulsion.

DNA & EVOLUTION

Cephalopods are an ancient species, with the first living over 500 million years ago. The earliest octopus fossil is 296 million years old, so early octopuses were around before the dinosaurs, when land-dwellers were still small reptiles. Suffice to say, you have to go a very long way back to find a common ancestor for cephalopods and hominids – our branches have been evolving separately for millions of years.

It’s unsurprising, then, that the DNA of an octopus is organised very differently to our own, enough that it has been described as “alien” by some scientists (several tabloid news sites took this to mean octopuses are actually extra-terrestrial, and a spate of misleading headlines ensued). In spite of this “alien” DNA, and our different evolutionary paths, octopuses have independently developed some similar features to us that we recognise as advanced, such as camera-like eyes, prehensile limbs, large brains and complex nervous systems. So when we’re looking in our own backyard for something utterly different, ancient, and yet still relatable, octopuses are a logical choice.

THE DEEP SEA

For us hominids, the deep ocean is another world – with its incredible pressures, cold temperatures, a lack of light and generally inhospitable environment, it’s somewhere we rarely go and could never live. Many cephalopods, however, make this world their home and have adapted to live there. Some of the most bizarre and rarely-seen types of squid live at great depths in conditions we could never endure. To visit them, we have to pack ourselves into something very similar to a space ship.

The deep sea is largely unknown territory we are still exploring, so it’s no surprise that fictional visitors emerging from the depths of space bear a resemblance to our very-distant ocean relatives.

LEGEND

History and legend also play a key role in our perception of cephalopods as alien and not-quite-real. Although accounts of giant squids date back to the 4th Century, and washed up carcases have long been mentioned and studied, it was only as recently as 2012 that the first footage of a live adult giant squid in its natural habitat was captured. The legend of the Kraken and accounts of sea monsters are thought to have been inspired by giant squid sightings.

These elusive creatures are so massive and so rarely seen alive that they have taken on a myth-like quality and inspired stories, hoaxes and conspiracy theories. With all that history, it’s not such a great leap to picture creatures like these piloting UFOs.

LOOKS

Finally, there’s a more emotional, instinctive reason we all know cephalopods make good aliens. Perhaps it was the first explanation that popped into your head when you read the title of this article. Cephalopods just look…creepy.

Something about cephalopod skin, tentacles, body shape, sliminess and motion has the capacity to repulse and frighten us. Add that they are carnivorous and often also poisonous, and the thought of tangling with a giant squid or an octopus becomes suitably distasteful. If you’ve ever seen footage of a cephalopod feeding it is shudder-worthy – reminiscent of a facehugger from Alien latching on.

Cephalopods also lay massive bundles of milky white eggs. And we all know what fertile ground that makes for dreaded alien hatchlings.

The bottom line is that if we’re looking for intelligent aliens that are vastly different from us, put us out of our comfort zone, frighten us, repulse us, amaze us, challenge our notions of intelligence, or remind us of a world vastly different from our own, we don’t have to look very far. Our fascinating cephalopod friends provide a wealth of inspiration.

Title image by JMD3.