agathodemon
/ˌaɡəθə(ʊ)ˈdiːmən/(also agathodaemon)
noun
A beneficent spirit or divinity, especially one manifested or depicted as a serpent or dragon.
Origin
Mid 18th century; earliest use found in Thomas Shaw (1694–1751), traveller. From (i) post-classical Latin agathodaemon kind of Egyptian serpent.