FifthColumn's Curse of Strahd
The singular form is Vistana, and is used irrespective of an individual’s gender.
The Vistani dress more colourfully than the average Barovian, and are often more cheerful and approachable to strangers. They camp in vardos and large tents, and cleave to an ancient, superstitious and clannish culture. They enjoy performing music and storytelling, and claim to be the best silversmiths, coppersmiths, and weavers in Barovia. They also are known for horse trading and blacksmithing, although most Barovians vocally distrust Vistani, claiming they are criminals, swindlers, and witches, among other things.
One famous Vistani tradition is fortune-telling, often accomplished by way of tarokka. During such a reading, the Outlanders were told by Madame Eva, among other things, to seek “a Vistana wandering in search of her mentor”, who she claims is an enemy of Strahd.