According to Johan Weyer, Buer is a demon of the second class who has the form of a star and is gifted with a knowledge of philosophy and of the virtues of medicinal herbs. He gives domestic felicity and health to the sick. He has charge over 15 legions.
Weyer, Johannes. Witches, Devils, and Doctors in the Renaissance: Johann Weyer, De Praestigiis. Edited by George Mora. Binghamton, N.Y.: Medieval and Renaissance Texts and Studies, 1991.