1. In Greek religion, a good divinity or genius and a deity of good fortune, sometimes in the form of a serpent: Primitive Greek belief sometimes regarded domestic snakes as agathodemons, the reincarnations of ancestors as spirits friendly to the household. An antonym of "cacodemon".
2. In Hermetic literature, a being regarded in part as a divinity, in part as a traditional teacher: He, the agathodemon, received a libation of pure wine at the end of each meal. In Hellenistic, and in later times, he was associated with Tyche, the goddess of luck, as a somewhat impersonal providence. He also has been portrayed as a serpent or as a young man with a horn of plenty and a bowl in one hand and a poppy and ears of corn in the other hand.