The word Duma (or sometimes Dumma) means “ghost” or “ancestor spirit” in several tribal languages of Andhra Pradesh and Odisha.

In the Gadaba tribe, for example, there is a process of transformation from life to death to benevolent ancestor spirit. For some time after a person dies, their Duma roams the village, visiting the houses of family members. People who died of natural causes don’t cause much trouble; their relations leave them offerings of rice and beer, and gradually they withdraw. After a few weeks, their individual life-force becomes reincarnated in the womb of a mother.

But those who die bad deaths stay volatile, their spirits wandering in the forest with malicious intent. Women who die in childbirth become Sunguni Duma; those who fall from trees, Mursu Duma; those killed by tigers, Bag Duma; those who hang themselves, Utshki Duma; and those who are struck by lightning, Betani Duma. Pacifying these spirits requires a special sacrifice of twelve animals. If the ritual is not done correctly, the Duma transforms into a horrifying demon called a Sagbo Duma, who causes people’s necks to swell up and makes them vomit blood.

It is said that some magicians can capture a peaceful Duma and turn it into a Betani Duma, using it as a weapon against their enemies.

Every three or four years, when there is a good harvest, a Gotar or Duma Puja is performed. This is an elaborate month-long ceremony in which the spirits of the deceased are pushed into a buffalo. The ceremony culminates in the sacrifice of many buffaloes, by slicing open their bellies and tearing out their intestines while they are still alive.

It is thought that the Gotar ceremony brings the Dumas peace, allowing them to join the benevolent ancestor spirits. Without it, the Dumas would go on wandering restlessly, attacking people and causing crops to fail.