One of the regular topics of discussion here is the ancient and admirable history of the gaff. They've been created and displayed for centuries, in forms as diverse as the Christian relics of Europe or the temple mummies of Japan. Marco Polo was even the first skeptic to expose their dubious origins.
That said, I think the Jenglot is the first example of a society incorporating gaffs as a regular part of their culture. In Indonesia they're the remains of sorcerers rejected by the Earth for their evil deeds. Or, possibly, the remains of holy men. It's hard to tell, since there's a whole lot of nuance lost in the English translations of Indonesian Malay. What's undeniable is that there are a whole lot of them in existence, of varying levels of craftsmanship.
It appears they're treated as something akin to house spirits by their owners. Although "spirits" isn't the right word, since they're apparently alive and fed with blood. In some cases human blood obtained legally from the Red Cross, if the Wikipedia article is to be believed.
I'd love to hear from anyone with actual knowledge of the subject.