Bifrons Medallion

This is a seal from the book "Lesser Key of Solomon".  According this text, the spirit Bifrons, is described thus

"The Forty-sixth Spirit is called
Bifrons, or Bifrous, or Bifrovs. He is an Earl, and
appeareth in the Form of a Monster ; but after a while,
at the Command of the Exorcist, he putteth on the shape
of a Man. His Office is to make one knowing in Astrology,
Geometry, and other Arts and Sciences. He teacheth
the Virtues of Precious Stones and Woods. He
changeth Dead Bodies, and putteth them, in another
place ; also he lighteth seeming Candles upon the Graves
of the Dead. He hath under his Command 6 Legions
of Spirits. His Seal is this, which he will own and submit
unto, etc"