Character
PoseidonNeptune in this translation
God of the sea and of earthquakes · brother of Zeus · father of Polyphemus

God of the sea and of earthquakes, brother of Zeus, and the reason the journey home takes ten years. Odysseus blinded his son the Cyclops Polyphemus, and Poseidon spends the poem making the sea as difficult as he can for him — most spectacularly by smashing his raft within sight of land. He is the one god Athena cannot simply overrule, only wait out. Butler calls him Neptune.
He never confronts Odysseus directly. His whole campaign is weather, delay and bad luck — which is what makes it feel like the sea itself holding a grudge.