Cross-posted from VoVatia.
One of the odd communities that seem to show up whenever an Oz book needs a bit of padding is the city of Thi, which appears in The Lost Princess of Oz. Located in the wild part of the Winkie Country, it is a neat and orderly but somewhat dull town, surrounded by an illusory wall. The people, known as Thists, have diamond-shaped bodies and heart-shaped heads and eat thistles, which don't harm them as their throats and stomachs are lined with gold. The thistles grow in the fields surrounding the city, and beyond that is land that turns around on occasion, making it appear to anyone coming toward the city that it is moving around the landscape. It's unclear who put these safeguards in place, but the Thists seem content to remain in their own city, isolated from the rest of Oz. The popular rumor in the area is that the Thists have chariots pulled by dragons, which is true after a fashion. They're actually mechanical auto-dragons, which sound impressive, but move quite slowly.
The High Coco-Lorum is the leader of the city, claiming to be merely a judge, but in reality holding pretty much absolute power. His rationale is that, if he actually declared himself ruler, it could lead to unrest. Hence, he runs things to suit himself without calling attention to the fact. So what is a High Coco-Lorum? Well, "high cockalorum," in addition to being a game, meant someone prideful who put on airs. Sources say it's basically just "cock" with a fake Latin ending, with "cock" used in the sense of a rooster strutting around. According to the Free Dictionary, "kockeloeren" is obscure Flemish onomatopoeia for a rooster's crow. In Rinkitink in Oz, King Rinkitink plans to make the man who wrote his favorite scroll, How to Be Good, a royal hippolorum, another nonsensical Latin-sounding title. "Hippo" does mean "horse," however, so maybe a hippolorum is someone on a high horse? Not that "lorum" means "high," but it still kind of fits.
At the end of David Hulan's The Glass Cat of Oz, Ozma sends Bungle to investigate unrest in Thi. I don't know whether Hulan had any ideas as to what this unrest might entail, but I have to wonder if someone got wise to the Coco-Lorum's posturing. I like to think that the Thists kept him in power anyway, because none of the others wanted to do the job. There's also a brief visit to Thi in Kim McFarland's A Refugee in Oz, and Thists are starring characters in Marin Elizabeth Xiques' The Bouncy Bunnies in Oz. In the latter, at least one Thist has friends outside the city, suggesting that the community is becoming somewhat less isolated.