Gigantomachy

Despite compelling Zeus to overthrow Cronus, Gaia still felt angry with Zeus and the Olympians for putting her children the Titans in Tartarus and she sought revenge and brought forth the Gigantes/Giants to do it. They numbered a hundred and Hera prophesised that they could only be defeated by gods and a hero working together, or the son of a mortal woman, this hero was Heracles.

They were led by Alkyoneus/Alcyoneus who could not be defeated in his homeland Pallene, Heracles lifted or lured him from his homeland and then killed him. The most prominent members were- Enkelados/Enceladus who was defeated by Athena who threw the island Sicily on top of him, Polybotes who was defeated by Poseidon throwing part of the island Kos, the rock Nisyros, on top of him, Porphyrion who is also given as king of the giants and was defeated by Zeus's lightning bolt and Heracles' arrows after he attempted to rape Hera, Eurymedon, another given king, Agrios and Thoon, killed by the Moirae with bronze clubs, Clytius killed by Hecate with flaming torches, Eurytus killed by Dionysus with his thyrsus/thyrsos, Gration killed by Artemis' arrows, Hippolytus killed by Hermes wearing the cap of invisibility, Mimas killed by Hephaestus with molten iron, and Pallas, killed by Athena.

Once the Giants were defeated by the gods Heracles shot them with arrows to make sure they were dead.

The Aloadae/Aloadai, brothers Otus and Ephialtes were two giant sons of Poseidon and Queen Iphimedeia who was also Poseidon's granddaughter and wife to her uncle Aloeus, a son of Poseidon. She is also given as the mother of Cercyon a king of Eleusis who challenged passersby to a fight and was eventually defeated and killed by Theseus, and possibly Sciron, a bandit who robbed people and kicked them over a cliff to be eaten by a sea monster or giant turtle, he too was killed by Theseus.

These brothers planned to overthrow Olympus by climbing up to it by stacking mountains on top of one another, they wished to take Artemis and Hera for wives. They captured Ares when he tried to stop them and sealed him in a bronze jar for thirteen monts, their stepmother Eriboea told this to the gods and was flayed alive by her husband Aloeus as a result, and Hermes was able to rescue Ares. Artemis defeated them by jumping between them in the form of a doe, they each threw their spear at her and killed each other instead.