Final answer:
Polyphemus is not a child of Gaia and Ouranos; he is the son of Poseidon and Thoosa from the Odyssey, unlike Brontes, Steropes, and Arges who are indeed children of Gaia and Ouranos.
Step-by-step explanation:
The Cyclops Polyphemus is NOT a child of Gaia and Ouranos. Polyphemus is actually a son of Poseidon and the nymph Thoosa, known from Homer's Odyssey, where he is encountered by Odysseus. Brontes, Steropes, and Arges, on the other hand, are the children of Gaia and Ouranos, known as the Hekatonkheires or the Hundred-Handed Ones, and are not to be confused with the Cyclopes who helped forge Zeus's thunderbolts.