Djinn

Known as "genies" in English, Djinn (singular form Djinni) have deep roots in Arab culture.
The Djinn first sprang from stories told by Indian, Persian, and Arabian storytellers and gained international fame when they appeared throughout the tales Scheherezade told in "The Thousand and One Nights". It is said that the Djinn are created from fire and can take on any form they choose-animal or human-and can be of any size (they have a human-like form and can take the shape of animals but only temporary unless it is their tribes animal protector.
Most of them are hostile, although some can be friendly. It is possible for magicians or wise men and women to gain power over a Djinn and use it to perform amazing and magical tasks. Be wary, for even a friendly Djinn is unpredictable and certainly anyone whobreaksan agreement with a Djinn will strongly regret it. Often Djinn take naughty pleasure in punishing people for wronging them, even unintentionally.

There are five different types of Djinn. The least powerful is the Jann, next come the Djinn and then the Sheytans, or devils. The Afrits, sometimes called Efreets are very powerful but the Marids are the most powerful and dangerous of all. Djinn are generally believed responsible for illness and mishaps

More information states that The Djinni are (mostly) evil spirits from Arabia. They came into existance before the world was fully formed and are made of black fire. Magicians, if powerful enough, can summon one, but if the magician shows even even a hint of weakness the Djinn it summoned can escape and wreck havoc on both the Magician and the world at large.