The Books of Occult Philosophy. Heinrich Cornelius Agrippa von Nettesheim (1486-1535) was a German magician, occult writer, astrologer, and alchemist. During his wandering life in Germany, France and Italy he worked as a theologian, physician, legal expert and soldier. After Agrippa's death, rumours circulated about his having summoned demons. In the most famous of these, Agrippa, upon his deathbed, released a black dog which had been his familiar. This black dog resurfaced in various legends about Faustus, and in Goethe's version became the "schwarze Pudel" Mephistopheles. The latest literary manifestation seems to be the Grim from the Harry Potter series.