The Hekatonkheires (also known as the Hundred-Handed Ones) are the brothers of the Elder Cyclops and Elder Titans, and have one hundred hands and fifty faces (depicting different emotions). They are classically the children of Gaea and Ouranos. They were the primeval gods of violent storms, Briares particularly of sea storms. Their brothers the Elder Cyclopes were also gods of storms, particularly of lightning.
Before the First Olympian War, the Hekatonkheires were imprisoned in Tartarus by Ouranos alongside their brothers: the Elder Cyclopes. They were guarded and tortured by Kampê until Zeus killed her and Poseidon freed the brothers by breaking their chains with his Trident. The Hekatonkheires helped the Olympians win the First Olympian War. Two of them, Cottus and Gyges, later served as guards to Tartarus' entrance. Briaries now lives in the underwater forges where Tyson works.
- Briares currently works with the Cyclopes in the underwater forges.
- In Percy Jackson: Sea of Monsters, a Hekatonkheire is seen serving at a café where Percy Jackson, Annabeth, Grover and Tyson to café. Here, however, he is shown with eight hands and one face instead of one hundred and fifty respectively.
|Species:||Centaur | Cyclopes | Dragon | Drakon | Eidolons | Empousa | Fire-Breathing Horse | Giants | Gorgon | Harpy | Hyperborean Giant | Ichthyocentaur | Karpoi | Katobleps | Laistrygonian Giant | Lycanthrope | Merpeople | Nikai | Nymphs | Pegasus | Satyr | Skolopendra | Stymphalian Birds | Telekhine | Blemmyae|
|Friendly Monsters:||Argus | Blackjack | Briares | Chiron | Don | Ella | Festus | Gleeson Hedge | Gray |Grover Underwood | Hippocampus | Mellie | Mrs. O'Leary | Ophiotaurus | Peleus | Scipio | Tyson | Tempest|
|Enemy Monsters:||Agrius and Oreius | Arachne | Basilisk | Charybdis and Scylla | Chimera | Chrysaor | Clazmonian Sow | Colchis Bull | Echidna | Euryale | Geryon | Joe Bob | Kampê | | Nanette | Manticore | Medusa | Minotaur | Nemean Lion | Polyphemus | Sphinx | Stheno | Typhon | Scythian Dracanae|
|Neutral Monsters:||Carnivorous Sheep | Cerberus | Erymanthian Boar | Gray Sisters | Gorgons | Furies | Flesh-Eating Horse | Gryphon | Siren|