Arbiel: A demon named in the Ars Theurgia. According to this text, Arbiel is one of twelve dukes in service to the infernal prince Hydriel. Hydriel governs no specific direction, and thus he and all the demons who serve him are said to wander through the points of the compass. Described as an aerial spirit, Arbiel has a subtle form and is best viewed in a crystal stone or scrying glass. When he manifests, he appears as a serpent with a woman's head and he has a fondness for places that are wet or swampy.
Source : Dictionary of Demons by Michelle Belanger