Odysseus defeated the Cyclops, who was Poseidon's son Odysseus defeated Poseidon's son the Cyclops
Odysseus is presumably killed by old age.
Antinous is the leading suitor killed by Odysseus.
Hydra
All of Odysseus' men are eventually killed before he gets to Ithaca.
The Lernean Hydra is killed by Heracles in his second of twelve labors. However why the Hydra is killed is never fully explained.
Odysseus defeated the Cyclops, who was Poseidon's son Odysseus defeated Poseidon's son the Cyclops
The scientific name for hydra is Hydra vulgaris.
Hercules/Heracles killed the Nemean Lion and the Hydra.
Odysseus is presumably killed by old age.
The Roman Name for The Hydra is just Hydra.
hydra
He killed the Hydra
Antinous is the leading suitor killed by Odysseus.
gorgon is another name for hydra
Lernaean Hydra.
In the end it was the Hydra that killed Hercules