typhon
The giant, Otus. (Not to be confused with Otis.)
The only one of the Gigantes that I know of to oppose Poseidon directly was Athos, but I don't know that he was "born" to.
The giant born to oppose the Greek goddess Artemis is Orion. In mythology, Orion is often depicted as a great hunter and is sometimes described as being born from the earth or as a child of the sea god Poseidon. His story frequently intertwines with that of Artemis, who eventually kills him, leading to his placement among the stars as a constellation. Their relationship embodies themes of rivalry and tragic fate in Greek mythology.
The Greek god Zeus was born on Mount Olympus.
There are a few giants which Ares fought; Mimas, Typhon and the Aloadai giants, Ephialtes and Otos who bound Ares.
Zeus was a Greek god. In Greek Mythology Athena came from Zeus's brain, in Roman Mythology Minerva was born from Jupiter's brain.
Zeus is a character from Greek mythology and no information on when he was born is known. It is said that he was born on the island of Crete to Cronus and Rhea.
Zeus
According to the Greek legend Athena was born out of Zeus's' head
On her father Zeus' lap.
Yes, Helios was likely fully grown when Zeus was born. As a Greek god, neither died.
Apollo is not a Greek goddess; he is a Greek god, born of the Olympian god Zeus and the Titan born goddess Leto.