Bathin (also Bathym, Mathim, or Marthim) is a demon described in demonological grimoires.
He is ranked as a duke in the Lesser Key of Solomon (as the eighteenth spirit) and Johann Weyer's Pseudomonarchia Daemonum (as the tenth spirit), where he is described as a serpent-tailed and muscular man riding a pale horse, who knows the properties of plants and stones, transports people across countries, and rules 30 legions of demons.[1][2] He also appears in the Livre des Esperitz, as "Machin," without the horse but ruling 37 legions of demons.[3] The German edition of The Grimoire of Pope Honorius describes Bathin (again by the name Machin) as teaching about and providing foreign plants and rocks.[4][5] In the Grand Grimoire, he (as Bathsin or Bathim) is listed as a subordinate of Fleurety.[6] According to Rudd, Bathin is opposed by the Shemhamphorasch angel Caliel.[7]