In Ars Magica, Jann are a type of jinn associated with oases. Ars Magica is also the title of a book by Judith Tarr. Ars Magica is a Role-playing game set in Mythic Europe In Geography, an oasis (plural oases) or Cienega ( Southwestern United States) is an isolated area of vegetation in a Desert, typically [1] They are the most individualistic of the jinn.
Caravans suffered or prospered at their hands, for it is said they could hide an oasis from those who had previously mistreated them or shown disrespect. Jann can take the form of a camel, generally white, and travel slowly between oasis under their control. They occasionally will disappear in a cyclone of sand. Jann will only rarely be found in cities, though many are said to have palaces at their favorite oasis. They often appear as a whirlwind of sand, or as a soldier in order to conceal themselves. [1]