A giant born to oppose Athena. He has dragon-scale legs and can breathe fire. He kidnaps Piper McLean's father to force her to betray her friends, but is defeated at Mount Diablo by Jason, Leo, and Piper with help from Zeus's lightning.

Gigantic son of Gaea, born to oppose Poseidon; marches an army on Camp Jupiter.

One of the twin Aloadae giants born to oppose Dionysus; partner of Otis; trapped Nico di Angelo in a bronze jar at the Colosseum.

One of the twin Aloadae giants born to oppose Dionysus; partner of Ephialtes.

Smoke-and-shadow giant bane of Hecate; quenches all magic; the final foe at the Necromanteion.

Earthborn giant of fear, anti-Hephaestus, lairs at the Sparta temple of chained Ares; killed by Piper.

Anti-Moirai giant who promises to kill the Fates; glimpsed in Piper's dream of the giants' council.

Earthborn giantess fought at the Acropolis; stunned by Piper's charmspeak.

A giant born to oppose Ares, who rejected violence and was cast into Tartarus as punishment. He lives peacefully in the abyss, tending a garden of drakon bones, and his particular hospitality to Percy and Annabeth when they find their way to his patch of the pit is one of the unexpected kindnesses Tartarus offers them.

Boeotian giant hunter with mechanical eyes, anti-Artemis; pursues Reyna and is killed by her channelling Athena.

Son of Poseidon and Gaia; runs a gladiator arena in the Labyrinth; gains strength from contact with his earth-mother and is defeated when Percy Jackson hoists him off the ground.