December 7, 2023

A Beginner’s Primer to Various Vermiform Invertebrates, or Sandworms, Three Ways

You scan the horizon, squinting in the bright light. There is only sand and sky for as far as you can see in all directions, heat shimmering off the dunes. It almost looks like the dunes themselves are moving. 


You squint harder, raise a hand to shield the sun from your eyes. They are moving, you can see the sand shift like the wake of a boat as something speeds beneath it, straight toward you. 

It’s time to talk about sand-dwelling carnivorous nightmare worms. 

The thing slithering toward you could be one of three creatures, largely distinguished from each other by their size. We’ll start with the smallest, but possibly most horrific. 

Mongolian Death Worm

Size: 2-6ft in length

Stories say that the Mongolian Death Worm resides in the Gobi Desert, and its name translates to “large intestine worm” so you know it must be lovely. Its first mention in print comes from an interview with the Mongolian Prime Minister in 1922, who described it as: “…shaped like a sausage about two feet long, has no head nor leg and it is so poisonous that merely to touch it means instant death.” It is said they can also spray their venom, that their thick skin is bright red, and that they lay their eggs in camel intestines. There are also stories of the worms shocking prey, like an electric eel. Basically, they’re a bad time. Pro tip: apparently carrying eggs in their intestines turns the host camel bright red, so steer clear of red camels. 

The worms from Tremors

Size: 30ft in length, 6ft in diameter

Tremors, Universal Pictures (1991)

Moving up the sandworm size scale, we reach the antagonist from the 90s cryptozoological classic Tremors. (Note: I refuse to call them Graboids and yes, I will die on this hill.) Like their fellow tubular invertebrates, these big bastards move under the sand and pop out to prey on whatever may be nearby. They are also eye-less, and rely on surface vibrations to hunt. However, unlike other sandworms, these particular beasts have tentacles that help grasp their food and drag them under the sand, like a more complex version of a Moray eel’s inner jaws. Avoiding this worm means avoiding not one, but four mouths. These odds are not amazing. 


Size: 1300ft in length, 130ft in diameter

Finally, the largest in our sandworm trio: the Shai-Hulud of Arrakis. 

Art by Nathan Rosario

Like its smaller brethren, the sandworms of Dune are essentially tubes with teeth that travel beneath the sand, attracted to vibrations. Unlike their smaller cousins, however, the Arrakan sandworms only eat humans and larger creatures by accident. Water is toxic to these behemoths, so hunting creatures that are 70% water is not a great survival strategy. They actually prey on tiny sand plankton–think of these sandworms as giant baleen whales, while Mongolian Death Worms and those Tremors guys are dolphins and orcas. 

These giants also produce a rare and invaluable mineral that is essential to the economy and ecology of the planet, so treating these giants as a threat to be eradicated is absolutely out of the question. These suckers are vital to human existence, so everyone just has to learn to live with them. 

So, what should you do if you see signs of a subterranean sandworm burrowing in your direction? All three of these species are thick-skinned and are drawn to vibrations. Moving from sand to rock is a universal strategy to avoid being swallowed. If there isn’t any rock nearby, throwing something in the opposite direction to distract while you stay completely still may work. If there’s some sort of vehicle nearby, getting off the sand may help, though Arrakan sandworms are known to swallow large machinery whole, so no promises. 

What about attacking? Well, downing a sandworm of any size will inevitably be difficult. You’d better have a lot of heavy duty firepower on hand if you hope to take down one of the “smaller” worms. You might be able to take down one of the largest sandworms with a pile of nukes, but that’s also a big “maybe.” (And forget riding them to safety if you aren’t a Freman.) 

If you intend to survive this encounter, your best bet is to get to more solid ground or freeze and distract. Don’t wait until you figure out exactly which worm you’re dealing with–you’ll be worm food by the time you do.