Abraxas, or Abrasax, was a word engraved on certain antique stones, called on that account Abraxas stones, which were used as amulets or charms by Gnostic sects.
Abraxas was an Archon with a chimera-like appearance (somewhat resembling a basilisk): he had the head of a rooster, the body of a man, and legs fashioned like snakes. Abraxas was redeemed and rose above the seven spheres and now reigns beyond the worlds. There are references to Abraxas in several gnostic writings.
The text below is based on the 1911 encyclopedia, and is probably not correct with respect to present-day research in Gnosticism, it needs to be checked.
The letters of abraxas, in the Greek notation, make up the number 365, and the Basilidians gave the name to the 365 orders of spirits which, as they conceived, emanated in succession from the Supreme Being.
These orders were supposed to occupy 365 heavens, each fashioned like, but inferior to that above it; and the lowest of the heavens was thought to be the abode of the spirits who formed Earth and its inhabitants, and to whom was committed the administration of its affairs.
In addition to the word Abraxas and other mystical characters, they have often cabalistic figures engraved on them. The commonest of these have the head of a fowl, and the arms and bust of a man, and terminate in the body and tail of a serpent.
Abraxas is the symbolic godhead in Hermann Hesse's novel "Demian".
In the fictional world of Charmed, Abraxas is a demon of the astral plane who destroys witches by demonising their powers. He appears on the 1st year anniversary of the Charmed Ones gaining their powers, as part of a Rite of Passage. The Book of Shadows says: Rite of Passage - Fight it with the power of one or else a more powerful Evil that awaits will destroy you.
His powers are Reviving defeated adversaries of the Charmed Ones by reading the Book Of Shadows backwards. He was vanquished by reciting the spell to receive a witches powers - Connect the Power of Three, to work as one.
