In demonology, Amaymon (also Amaimon, or Amoymon) is a Prince of Hell, and, according to some Grimoires, the only one who has power over Asmodai.
A curious characteristic of this Spirit is alleged in almost all copies of the Goetia in English, to wit that during the Evocation of Asmodai to visible appearance, the Exorcist must stand upright with his Cap or Headdress removed in a show of respect; for if he does not it is Amaymon who will deceive him and doom all his work. According to Joseph H. Peterson, editor of “The Lesser Key of Solomon” (Weiser 2001) this is a “bizarre translation of ‘si vero coopertus fuerit'” (Page 21 Footnote 57) by Scot in his “Discoverie of Witchcraft” which contains a translation by Scot of Pseudomonarchia Daemonum by Johannes Weyer. Peterson’s edition includes as an appendix, a copy of Weyer’s Pseudomonarchia Daemonum in the original Latin where we find (Page 242) Cum hujus officia exercet exorcista, fit fortis, cautus & in pedibus stans: si vero coopertus fuerit, ut in omnibus detegatur, efficiet: Quod si non fecerit exorcista, ab Amaymone in cunctis decipietur which translates to When the exorcist performs his offices, he should be strong, cautious and standing on his feet: if he will be truly overwhelmed he will bring it about that in all things he is unprotected: But if the exorcist does not, by Amaymon he will be deceived in whole.
In the original text by Johannes Weyer, there is nothing about taking off caps or headdresses when evoking Asmodeus. The curious characteristic replicated in every known English text of the Goetia seems to arise from laziness on the part of Scot and generations of scribes replicating the English text without checking the original Latin.
Amaymon is said to have a deadly poisonous breath.
The Lesser Key of Solomon states the Exorcist or conjurer must be in possession of a Silver Ring, duly consecrated and worn on the middle finger as a form of protection against this poisonous astral breath.
According to Pseudomonarchia Daemonum he is the King of the West, although for some translations of The Lesser Key of Solomon he is King of the East (Although some translations of The Lesser Key of Solomon consider Belial, Beleth, Asmodai and Gaap kings of the four cardinal directions, though not giving detail on the cardinal point each rule).
According to the grimoire The Book of the Sacred Magic of Abramelin the Mage translated by S.L. MacGregor Mathers, Amaymon (as Amaimon) was one of the eight Sub-Princes, described as an Egyptian devil whom Abramelin restrained from working evil from the third hour till noon and from the ninth till evening.