The Tcho-Tcho, or Tcho-Tcho people, are a fictional human people or human-like race in the Cthulhu Mythos.
The Tcho-Tcho are first mentioned in August Derleth's 1933 short story "The Thing That Walked on the Wind", in which a character refers in passing to "the forbidden and accursed designs of the Tcho-Tcho people of Burma". Later that year, in "Lair of the Star-Spawn", co-written with Mark Shorer, Derleth expanded on the Tcho-Tcho, describing them as a short, hairless people that worship Lloigor and Zhar.
In H. P. Lovecraft's "The Shadow Out of Time" (1936), they are described as "abominable". In Lovecraft's ghost written "The Horror in the Museum," John Rogers claims that he had visited a ruined city in Indo-China where the Tcho-Tchos once lived.
In T. E. D. Klein's novella Black Man with a Horn, first published in New Tales of the Cthulhu Mythos in 1980, the Tcho-Tchos are described by an American missionary who has met them as "the nastiest people who ever lived(...) They'd been living way up in those hills I don't know how many centuries, and whatever it is they were doing, they weren't going to let a stranger in on it".
In the Call of Cthulhu adventure game book "Curse of the Chthonians" the Tcho-Tchos are referred to as a degenerate and cannibalistic race that worship strange gods. They are noted to have been living in southeast Asia in the 1920s, having migrated from Tibet, their homeland. Apparently they follow an ancient legend about migrating toward the rising sun, which has caused speculation that they may have at one time reached Europe and established settlements there. A Basque legend of "dark dwarves that left their home in the Pyrenees at the command of their priests" supports that theory.
The campaign At Your Door, for the Cthulhu Now supplement of the Call of Cthulhu roleplay setting, claims that some Tcho-Tcho have actually integrated themselves into modern society, masquerading as just another harmless ethnic group. It also claims that a delicacy of their cannibalistic cuisine, which they secretly dole out to unsuspecting diners at their "ethnic restaurants", is a dish called bak bon dzhow. This dish is composed of human ganglia mashed into a thick paste and is usually served in accompaniment to other "white pork" (human flesh) based dishes. Bak bon dzhow means, literally, human ganglia paste in their native tongue, though inquisitive outsiders are always told that the translation is "White Pork Sauce". Non-Tcho-Tchos who partake of it dream of lustily partaking in a vile cannibal feast the next time they sleep.
In the Delta Green role playing game, the Tcho-Tcho are said to be cannibalistic criminals devoted to the worship of the Great Old Ones and to have received funding and weapons by the CIA-owned campaign of support to anti-Vietnamese ethnic groups in Indochina during the early 1970s, via Tiger Transit, an Air America-style front company. This background is also mentioned in the d20 System version of the Call of Cthulhu roleplay setting
Tcho-Tchos attack Charles Fort and Arthur Conan Doyle on a couple of occasions in Gordon Rennie and Frazer Irving's 2000 AD strip Necronauts.
In the novel The Spiraling Worm by David Conyers and John Sunseri, Tcho-Tchos are presented as combatants during the Vietnam War who utilise the powers of an Outer God to gain military intelligence on their American foes.
Tcho-Tchos are briefly mentioned by "Oliver Haddo" in The League of Extraordinary Gentlemen: Black Dossier.