The Mongolian Death Worm: Gobi's Olgoi-Khorkhoi

You are crossing the Gobi's red gravel in the back of a jeep when the driver slows, points at a stretch of empty dune, and refuses to go near it. Nothing moves out there. That, he says, is where the olgoi-khorkhoi lives, and pointing at it is already unwise.

The worm the herders will not name

The Mongolian death worm — olgoi-khorkhoi, roughly "large intestine worm" — is a fixture of southern Gobi folklore long before any outsider wrote it down. Herders describe a fat, sausage-shaped creature about half a metre long, dark red, with no visible head or legs, so that either end could be its mouth. It surfaces in the hottest months, June and July, usually after rain, and spends the rest of the year buried in sand. The taboo is genuine: many nomads simply decline to discuss it, and pointing toward its supposed ground is thought to invite trouble.

The creature's reputation rests on how it kills. It is said to spray a corrosive yellow venom that turns whatever it touches the same acid colour, and in the more dramatic tellings to discharge something like electricity strong enough to drop a camel and its rider from a distance. Touch it, or even the ground it crossed, and you die. None of this has ever been filmed, trapped, or recovered.

From an American explorer to Czech expeditions

The worm entered the written record through Roy Chapman Andrews, the American Museum of Natural History naturalist often floated as a model for Indiana Jones. In "On the Trail of Ancient Man" (1926) and again in "The New Conquest of Central Asia" (1932), he relayed the death-worm accounts he collected from Mongolian officials, while making clear he never saw the animal and doubted it existed. His scepticism did not travel as far as the legend did.

Decades later the Czech engineer and adventurer Ivan Mackerle turned the search into a genuine quest, mounting expeditions in 1990 and again in the early 2000s, at one point trying to lure the worm up by detonating charges to mimic thunder. He came back with stories, not specimens. British zoologist Richard Freeman led a Centre for Fortean Zoology expedition in 2005 and hit the wall every hunter hits: consistent local testimony, zero physical evidence.

What it might actually be

The sober candidates are unglamorous. A legless, blunt-ended, sand-dwelling animal already exists in Central Asia in the form of the Tartar sand boa, Eryx tataricus, whose thick body and rounded tail could pass for a two-ended worm to someone who saw it briefly and then fled. Worm lizards, or amphisbaenians, offer another template for the "no head or tail" description. The venom-spraying and electric powers look like folklore doing what folklore does: explaining sudden death in a harsh place where dehydration, snakebite and heatstroke kill without warning.

What the tidy zoology does not quite dissolve is the consistency. Herders separated by hundreds of kilometres, with no reason to coordinate, describe the same red sausage, the same season, the same dread, and back it with a taboo strong enough to make a paid guide refuse a short walk. That is either a very stable folk memory or something still uncatalogued under the sand.

Below, readers have filed their own Gobi encounters and near-misses and voted them True, Fake or Not sure. Read them with the driver's caution and cast your own verdict.