https://en.wikipedia.org/wiki/Kuman_Thong
Kuman means "Sanctified young boy", Thong means golden.
The authentic Kuman Thong originated in a practice of necromancy. They were obtained from the desiccated fetuses of children who had died whilst still in their mothers' womb. The witch doctors were said to have the power to invoke these stillborn babies, adopt them as their children, and use them to help them in their endeavours.
According to ancient Thai manuscripts used by practitioners of black magic (Thai: ไสยศาสตร์ Saiyasat), first the unborn fetus was surgically removed from the womb of its mother. Then the body of the child would be taken to a cemetery for the conduction of the proper ceremonial ritual to invoke a Kuman Thong. The body was roasted until dry whilst the witch doctor chanted incantations of magical script. Once the rite was completed, the dry-roasted Kuman was painted with Ya Lak (a kind of lacquer used to cover amulets and Takrut with gold leaf) and covered in gold leaf. Thus this effigy received the name of “Kuman Thong”, meaning “Golden Little Boy”.
Some Kuman effigies were soaked in Nam Man Phrai, a kind of oil extracted by burning a candle close to the chin of a dead child or a person who died in violent circumstances or an unnatural death. This is much less common now, because this practice is now illegal if using fat from human babies for the consecrating oil. Occasionally there are still some amulets obtained through the authentic methods appearing in the market. Some years ago a famous monk was expelled from the Buddhist Sangha for roasting a baby. He was convicted, but later continued to make magic as a layperson after his release.