Ophis

Ophis - "head of the rebellious angels" - so described by the Assyrian author Phercies and quoted by Barrett in The Magus; also referred to in Butler, Ritual Magic.  Ophis was revered by the ophites as a symbol of divine wisdom who, in the form of a serpent, befriended Adam and Eve in Eden, persuading them to eat of the forbidden fruit (as a service to man).  In Barrett, The Magus II (opposite p.46), Ophis is pictured as a demon. (a)

Resource List - all entries are taken verbatim from the original source:

(a) "The Dictionary of Angels" by Gustav Davidson, © 1967