The giant, Otus. (Not to be confused with Otis.)
typhon
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.
Apollo was born as a Greek God, he was then born with his "powers".
Apollo was born on Delos by Leto.
Apollo is not a Greek goddess; he is a Greek god, born of the Olympian god Zeus and the Titan born goddess Leto.
There are a few giants which Ares fought; Mimas, Typhon and the Aloadai giants, Ephialtes and Otos who bound Ares.
Apollo was born on the Greek island of Delos. According to Greek mythology, Delos is the sacred birthplace of Apollo and his twin sister Artemis.
Apollo was born a Greek god, his father being Zeus and his mother being Leto a Titan born goddess.
Greek myth provides no timeline.
Apollo was born a Greek god, son of the Olympian god Zeus and the Titanis Leto.
Most scientists believe that Apollo the Greek god, was born to the mother of Leto, and to the father of Zeus.