Buer is a spirit that appears in the 16th century grimoire Pseuomonarchia Daemonum and its derivatives, where he is described as a Great President of Hell, having fifty legions of demons under his command. He appears when the Sun is in Sagittarius. Buer teaches Natural and Moral Philosophy, Logic, and the virtues of all herbs and plants. He also heals all infirmities, especially of men, and gives good familiars.