The demon Ansoryor appears in the grimoire The Book of Oberon
From The Book of Oberon, Dan Harms edition:
Ansoryor or Antyor, a lord; and appeareth like a warlike knight, riding upon a pale ass, and he beareth in his hand a viperous eagle, and he is very excellent in physic, and in necromancy, in pyromancy, hydromancy, and in all arts, and giveth true answers of things past, present, and to come, and knoweth the natures and properties of herbs, stones, and trees, and giveth to one every liberal art, and that to the master and maketh him perfect therein in seven days, and desireth sacrifice, and thou bind him not well, he will deceive the master, and hath under him 20 legions.
Timeline of related events
1577Book of Oberon completed (lists this demon)