Field of Science

The Mongolian Death Worm

This would have been a comment on a recent post by Darren Naish at Tetrapod Zoology on the behaviour of amphisbaenians, but the commenting system they have at Scientific American these days means that any comment on a post more than a couple of days old will never be seen by anyone. As such, I'm posting it up here:

PhilJTerry's comment in response to Darren's post: "As I love introducing cryptozoology into the conversation wherever possible - are Amphisbaenians a likely influence for the Mongolian Death Worm? Can they live in desert environments?"

Image from National Geographic.

For those not already aware, the "Mongolian death worm" or "olgoi-khorkhoi" is a supposedly incredibly dangerous animal found in the deserts of Mongolia. It's first mention in Western literature came in Roy Chapman Andrew's (1926) On the Trail of Ancient Man. Andrews heard about the animal in a meeting with Mongolian officials:


Since then, there have been a number of expeditions have been conducted in search of the Premier's "allergorhai-horhai"; all have come up fruitless. Various opinions have been expressed as to what the stories may have been based on, with the most popular suggestions being some sort of reptile (Darren says in his response to the above comment on the original post that he "could buy that the stories are based on exaggerated tales of erycine boas or something"). For my part, I suspect that the question of the 'original identity' of the Mongolian death worm may be a futile one. When I first heard Andrews' account, I was not reminded of an amphisbaenian or a boa; I was immediately put in mind of a drop bear.

I feel almost certain that Andrews was being told a local tall tale, a popular joke at the expense of visiting travellers. The nature of Andrews' response to the officials suggests that he was in on the joke and more than happy to play his part in communicating it. Admittedly, other accounts of the Mongolian death worm have been recorded at more recent dates. And in the same way, I've never seen a drop bear myself, but I can assure you that my cousin did once and got the fright of his life. Be careful. They're out there.


  1. When I worked for the National Park Service I occasionally met people who thought the jackalope was real, from postcards. It was awkward to explain that they weren't but I felt obligated.
    See Origins of the Jackalope
    (hope that worked)

  2. It worked, and it was certainly interesting to learn how the jackalope came to be. The jackalope stands out a little among the tall-tale beasts in that it is essentially benign; most of them (like drop bears) seem to be somehow dangerous, making them more likely to get a rise out of the person being told about them. For my part, I hesitated briefly to write this post because it seemed somewhat gauche and humourless to suggest that a tall-tale animal might actually be a hoax.

    One interesting detail that I forgot to mention in the post is that the Mongolian death worm is apparently supposed to be associated with the Maltese fungus Cynomorium coccineum (which is not a fungus but a parasitic plant). And as such, I suspect it's not a coincidence that the inflorescence of this plant looks a lot like what someone would be told to look out for if trying to avoid the death worm.

    1. If the Mongolian Death Worm is closely associated with the Cynomorium, as Dr Shuker suggests, then it could be a trade protection tale. The collection of suǒ yáng Cynomorium coccineum subsp. songaricum for use in Chinese herbalism was and is still a very large and valuable trade. It is used as an aphrodisiac and sexual medicine particularly against impotence and infertility. Among other things it nourishes the sinews and moistens the intestines. Contraindicated in those with excessive erections. First mentioned in China in the text "Supplement to the Extension of the Materia Medica" from 1347 CE.

      The Knights of Malta also had a very rewarding trade monopoly in Cynomorium in the 16th Century, which gave it the name Maltese fungus in Europe. The western variety (Cynomorium coccineum subsp. coccineum) is also used in North African and Middle Eastern herbalism, known there as tartous (tarthuth, etc.) and the "treasure of drugs".

      The dried herb (inflorescence?) is now available for only $9 for 500g in the US. The one I tried had a pleasant, sweet taste.

      I would say the Mongolian Death Worm is comparable to the old tales of mandrake, also a very valuable commodity collected by specialists from the wild. The rumour that mandrake's scream on being uprooted would kill the unprepared collector was clearly designed by the rhizotomoi to keep a monopoly. The details on how collectors got around the problem (ivory tools, dogs, circles) helped explain the high price they were charging. Viral advertising that still gives mandrake a distinct cachet over 2300 years later.

      The other stories that mandrake could glow in the dark, move around at will and would giggle at the aspiring collector's embarrassment are not so well-remembered.

    2. Interesting suggestion, Pattock. It should be noted that your and Vlad's suggestion below are not mutually exclusive.

      The collected part of the Maltese fungus is the inflorescence, yes. The vegetative part of the plant is below the ground, attached to its host's roots.

  3. The tales I've heard in Mongolia were remarkably similar to Turkmen tales about the terrible two-headed snake (dwarf sand boa Eryx miliaris). I am pretty sure the Mongolian version is about the same species and/or the larger Tartar sand boa (E. miliaris).

  4. David Marjanović14 March 2017 at 21:19


    Apparently Darren does get a message. :-)

  5. Vlad: good to have some input from someone who's heard the stories directly!

    David: I thought I could recall Darren complaining a while back that even he didn't get any notification about new comments. If SciAm has corrected that oversight, that's at least some improvement.

    1. David Marjanović10 April 2017 at 23:28

      More likely he checked manually. I always check the last 3 or so of his posts for comments.


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