Why was Poseidon so angry with Odysseus?
The cyclops, Polythemus, was Poseidon’s son. Odysseus had blinded him in order to escape from his cave and so Polythemus prayed to his father for revenge on Odysseus and asked for him not to return home but if he did happen to, it would be alone and had taken him years (which happened due to Poseidon’s interference in Odysseus’ travels home).