Megaera is one of the three Furies representing grudges, jealousy, and envy.
Magaera goes to the beach along with Alecto and Tisiphone to collect Hades' Helm of Darkness from Percy Jackson, and sees that Percy was not responsible for stealing Zeus' master bolt, Ares, Luke Castellan, and Kronos were.
- Megaera was the name of Hercules' first wife whom he murdered after being cursed by Hera.
- She is not much mentioned unlike her sisters.
|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|