Bathin is a Great Duke of Hell in Christian demonology.
Other spellings: Bathym, Mathim, Marthim.
According to Pseudomonarchia Daemonum Bathin is a Great Duke of Hell with thirty legions of demons under his command.
Bathin is depicted as a strong man with the tail of a serpent, riding a pale horse.
Bathin knows the virtues of precious stones and herbs, and can bring men suddenly from one country to another.
Bathin [Bathym], sometimes called Mathim [Marthim], a great duke and a strong, he is seene in the shape of a verie strong man, with a serpents taile, sitting on a pale horsse, understanding the vertues of hearbs and pretious stones, transferring men suddenlie from countrie to countrie, and ruleth thirtie legions of divels. Pseudomonarchia daemonum - Johann Wier (1583)
The Eighteenth Spirit is Bathin. He is a Mighty and Strong Duke, and appeareth like a Strong Man with the tail of a Serpent, sitting upon a Pale-Coloured Horse. He knoweth the Virtues of Herbs and Precious Stones, and can transport men suddenly from one country to another. He ruleth over 30 Legions of Spirits. His Seal is this which is to be worn as aforesaid. Goetia - S. L. MacGregor Mathers (1904)