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Olgoi-Khorkhoi: The Mongolian Death Worm

Mongolian tradition holds that a strange and deadly worm lives beneath the sands of the Gobi desert.  

by Brian Dunning

Filed under Cryptozoology

Skeptoid Podcast #344
January 8, 2013
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Mongolian Death Worm

An artist's interpretation
of the Olgoï-Khorkhoï
Photo credit: Wikimedia

Few creatures from the annals of cryptozoology are as dramatically named as the Mongolian Death Worm, or as it's known to the locals, the Olgoï-Khorkhoï. It is said to cruise the sands of Asia's vast Gobi desert, unseen and unknown to all but those unlucky few believed to have had usually fatal encounters. A tiny but extraordinary body of literature is all that endorses the existence of such a creature — none have ever been captured, photographed, or reliably documented — and yet the tales remain, of this bizarre headless worm that kills any who touch it.

Why even discuss a creature whose very existence is fanciful, and that's so rarely mentioned in pop culture that most are scarcely even aware of it? Because despite these red flags, some take it very seriously. Cryptozoologists spend real money to hunt for the Olgoï-Khorkhoï. Authors do their best to assign it a plausible place in taxonomy. Resources and efforts have been expended trying to explain, in legitimate zoological terms, the creature's marvelous abilities. Something about the Mongolian Death Worm has tempted the curious to pursue a being that's no more likely to be real than the cutout Cottingley Fairies or the Lucky Charms leprechaun. As we find often on Skeptoid, how and why the story exists turns out to be more intriguing than the story itself.

The Olgoï-Khorkhoï lives under the sand, but during the summer months of June and July it may occasionally rise up to attack and kill. It's less than a meter long, with the appearance of a sausage; in fact its name translates as intestine worm. Both ends look the same with no discernible head or tail. In some accounts, it is blood-red in color. Touching the worm confers instantaneous death, either by toxin or electric shock. Get within several meters of one and it can kill you just as effectively with either of squirt of venom or an electrical jolt. From what I could find, the Olgoï-Khorkhoï enjoys a reputation in Mongolia about the same as that of ball lightning in the Western world: just about everyone knows someone who's seen it, but few admit having seen it for themselves.

The earliest known English language account of the little beastie appeared in 1922 with Asia Magazine's publication of selections from zoologist Roy Chapman Andrews' 1926 book On the Trail of Ancient Man, a narrative of his large, well-organized and well-funded scientific expedition throughout Mongolia to document its zoological history. It was the second expedition of a series sponsored by the American Museum of Natural History. Over 50 scientific papers were published by various scientists in Andrews' party as a result of this one expedition alone.

In the summer of 1919, Andrews and his party were in the Mongolian capital, Ulaanbaatar, then called Urga. They were to meet the Premier, the Minister of Foreign Affairs, and other officials in the Mongolian cabinet to finalize the details of their expedition permits. Andrews wrote:

Then the Premier asked that, if it were possible, I should capture for the Mongolian government a specimen of the allergorhai-horhai. I doubt whether any of my scientific readers can identify this animal. I could, because I had heard of it often. None of those present ever had seen the creature, but they all firmly believed in its existence and described it minutely. It is shaped like a sausage about two feet long, has no head nor legs and is so poisonous that merely to touch it means instant death. It lives in the most desolate parts of the Gobi Desert, whither we were going. To the Mongols it seems to be what the dragon is to the Chinese. The Premier said that, although he had never seen it himself, he knew a man who had and had lived to tell the tale. Then a Cabinet Minister stated that "the cousin of his late wife's sister" had also seen it. I promised to produce the allergorhai-horhai if we chanced to cross its path, and explained how it could be seized by means of long steel collecting forceps; moreover, I could wear dark glasses, so that the disastrous effects of even looking at so poisonous a creature would be neutralized. The meeting adjourned with the best of feeling; for we had a common interest in capturing the allergorhai-horhai. I was especially happy because now the doors of Outer Mongolia were open to the expedition.

Ten years later Andrews co-authored an account of further expeditions in the 1932 book The New Conquest of Central Asia, in which he repeated this brief tale, and added:

I have never yet found a Mongol who was willing to admit that he had actually seen it himself, although dozens say they know men who have. Moreover, whenever we went to a region which was said to be a favorite habitat of the beast, the Mongols at that particular spot said that it could be found in abundance a few miles away. Were not the belief in its existence so firm and general, I would dismiss it as a myth. I report it here with the hope that future explorers of the Gobi may have better success than we had in running to earth the Allergorhai horhai.

With so much belief in its existence saturating Mongolia, I turned to the literature to see what Mongolians had to say on it. That's when I hit the big barrier. The language barrier. Mongolian is a very isolated language, and very little literature has been translated. As a member of the Altaic language family, Mongolian has little connection to the more common but geographically closer Chinese languages; and it's written in the Cyrillic alphabet. Thus, more of it has been translated into Russian than into any other language, and even that has been a tiny amount. No doubt there is plenty of Mongolian literature out there that sheds much more light than I'm able to here, but fortunately for the Olgoï-Khorkhoï, there was an enthusiastic ambassador to the outside world.

He was cryptozoology author Ivan Mackerle (1942-2013), an automotive engineer and inveterate enthusiast of adventure and the call of mystery. Mackerle loved to take his amphibious Volkswagen Schwimmwagen into the backcountry to explore. He was Czech, living in Prague, so he had slightly improved access to Russian and Mongolian literature on the Death Worm. He managed to collect just about everything he could that was written about the Olgoï-Khorkhoï, and it was he who introduced it to Western audiences. Mackerle is the one who first made modern publication of Roy Chapman Andrews' account; if it wasn't for him, Andrews' little anecdote would probably have remained buried and unknown on some dusty library shelf.

Mackerle had first been inspired by Soviet science fiction author Ivan Efremov who wrote a short horror story called Olgoï-Khorkhoï in a 1954 collection called Stories. In it, a party of geologists is terrorized by the worms. Efremov was also a professional paleontologist, and had heard stories about the creature back in 1946 when he accompanied a Soviet Academy of Sciences paleobiological expedition into the Gobi desert. Four years after his short story, Efremov wrote a nonfiction book about the Soviet expedition called The Wind's Path, in which he detailed conversations with Mongols about the Death Worm.

Mackerle was hooked. He bravely dove into Mongolian literature, and was able to track down a few more references. In a 1987 book called Altajn Tsaadakh Govd about the land and legends of a part of the Gobi, he found (and provided this translation of) this brief mention of the creature:

Another more dangerous animal also lives in the Gobi, the allghoi khorkhoi. It resembles an intestine filled with blood, and it travels underground. Its movement can be detected from above via the waves of sand that it displaces.

He found a slightly more dubious account in the 1990 Mongolian book Braid of Mongolian Secrets, in which the author cited a Soviet scientist named A. D. Simulkov as having described the creature back in 1930, though he gave no source, and there do not appear to be any other mentions anywhere of such a scientist or such a report.

Nevertheless, Mackerle and a small group of companions made two trips into the Gobi desert to search for the worm in 1990 and 1992. Inspired by Frank Herbert's 1965 novel Dune in which giant fictional sand worms could be brought to the surface by rhythmic thumping, Mackerle and his party tried various methods of pounding on the sand. They constructed a motor-driven "thumper" and even detonated small buried explosive charges. Mackerle's science-fiction inspired methods never succeeded in finding an Olgoï-Khorkhoï, but they did provide the source material for what became the seminal popular work on the Death Worm.

Mackerle first published his account in the Czech magazine Reflex in 1991, then again in another Czech magazine Filip in 1992. His articles finally appeared in English in 1992 and 1994, in a pair of semi-regular newsletters that focused on UFOs and New Age mysticism called The Faithist Journal and World Explorer. He also managed to put together a 30-minute documentary for Czech television called "The Sand Monster Mystery" that was broadcast in 1993.

After Mackerle's articles appeared, the Olgoï-Khorkhoï exploded onto the cryptozoology scene. Based (it appears) entirely upon Mackerle's work, you can now find the Mongolian Death Worm in virtually any book on cryptids published since the early 1990s. Every single published account I found included no sources other than Ivan Mackerle and the few accounts unearthed by him. It appears that scarcely any author or researcher has done anything original on the subject, and certainly nobody has produced any photographs or evidence. If ever there was a case of a cryptid being the brainchild of one man, it's the Olgoï-Khorkhoï.

But what about all that widespread popular belief, that kept Roy Chapman Andrews' skepticism at bay? Well, although widespread popular belief is frequently found alongside things that are true, it doesn't make anything true. It doesn't make angels or the afterlife or telekinesis true. The animals that are known and cataloged are that way because we have specimens of them, not because there was a local tradition about them. Think of how absurdly the taxonomy would have to be expanded if every local tradition was sufficient, on that merit alone, to warrant the scientific acceptance of a new species. Dragons, snipes, and Yowies would have to be in our textbooks. We can respect the local tradition without having to accept it as literal fact.

So enjoy your trip to the desert, and enjoy your science fiction short stories about Death Worms. But don't worry too much, unless, of course, the sand beneath you begins to squirm.

By Brian Dunning

Please contact us with any corrections or feedback.


Cite this article:
Dunning, B. "Olgoi-Khorkhoi: The Mongolian Death Worm." Skeptoid Podcast. Skeptoid Media, 8 Jan 2013. Web. 28 Nov 2015. <>


References & Further Reading

Andrews, R. On the Trail of Ancient Man. New York: Doubleday, 1926. 103-104.

Clark, J. Cryptozoology A to Z: The Encyclopedia of Loch Monsters, Sasquatch, Chupacabras, and Other Authentic Mysteries of Nature. New York: Simon & Schuster, 1999.

Efremov, I. Stories. Moscow: Foreign Languages Publishing House, 1954.

Mackerle, I. "In Search of the Killer Worm of Mongolia." The Faithist Journal. 1 Sep. 1992, Volume 1992.

Shuker, K. The Beasts that Hide from Man: Seeking the World's Last Undiscovered Animals. New York: Paraview Press, 2003. 25-45.

Tsevegmid, D. Altajn Tsaadakh Govd. UlaanBataar: Ulsyn Hevleliin Gazar, 1987.


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