A serpent is not one symbol
Opponent, world-boundary, host: three beings with very different narrative work.
Begin with the action
Typhon challenges Zeus in Hesiod’s account of divine sovereignty. Jörmungandr encircles the inhabited world and confronts Thor in Eddic narratives. The enormous serpent in the Egyptian Shipwrecked Sailor speaks with a visitor, recounts loss, and promises a return home. Form alone does not settle whether a creature is helpful, threatening, or both.
Scale is part of the story
The bodies of these beings make power imaginable at a scale beyond ordinary human experience. But their places are not equivalent: an opponent in a succession struggle, a creature in cosmic geography and prophecy, and an island host inside a sailor’s account have distinct functions.
Do not turn a motif into a dictionary
A chart that states “serpent means evil” would fail on the Egyptian example and flatten the others. “Serpent means wisdom” would be equally inadequate. Even positive or negative labels can conceal changes within a single narrative. Read what a being says, does, and makes possible before attaching a meaning.
The limit of the evidence
This comparison concerns selected literary descriptions. It does not reconstruct every ancient attitude to snakes, equate religious figures, or establish borrowing. Images on the atlas are original editorial symbols, not archaeological evidence for the stories. For a particular ancient object, an object record and its context would be necessary.