Herkus
The Herkus are the extraordinarily strong but very thin people who rule the City of Herku and keep giants as slaves.
First named in The Lost Princess of Oz, ch. 6
Beyond the Merry-Go-Round Mountains it is said the Thistle-Eaters and the Herkus live.”
What the books say it is
region live back beyond the thistles and the twisting lands 1 chapter
The Herkus live back of us, beyond the thistles and the twisting lands, and they are not very nice people to meet, I assure you.
The Lost Princess of Oz, ch. 9