Shax is a Great Marquis (and a Duke to some authors) of Hell with thirty legions of demons under his command.
Shax is depicted as a stork that speaks with a hoarse but subtle voice; his voice changes into a beautiful one once he entered the magic triangle.
Shax takes away the sight, hearing and understanding of any person under the conjurer's request, and steals money out of kings' houses, only to return it 1200 years later if everything is still in order. He also steals horses and everything the conjurer asks. Shax can also discover hidden things if they are not kept by evil spirits, and sometimes gives good familiars, but sometimes those familiars deceive the conjurer.
If he is confined to a triangle, he will speak truth on supernatural matters, point out hidden treasures not guarded by evil spirits, and obey the exorcist. If he is not confined, he will lie and not always obey the exorcist.
Shax is a fallen angel who appears as a stork and is a stealer of money.