Lamia had attracted the attention of Zeus and accepted his courtship. But upon doing so, faced the wrath of the jealous Hera. Hera killed her children, Altheia and Demetrius, and then Lamia was turned into a monster. Angered at the goddess, she used an incantation to allow all the monsters in the world to sense the taint of half-bloods, so that they could always be found. Lamia did it out of spite so that Hera would finally understand her pain of losing her children after so many demigods have been killed.
Lamia is returned to life by Gaea, who sent her to kill Alabaster C. Torrington, another child of Hecate. Alabaster tried to kill her several times, but because Gaea has opened the Doors of Death, and also because Thanatos was chained by Alcyoneus, Lamia wouldn't stay dead - she would just turn to black dust and reform within minutes. After a speech given by Howard Claymore about his new book (the sponsor of which is Lamia), she notices Claymore and Alabaster interacting and pursues Claymore, only to discover later, he's an ally of Alabaster. She curses Claymore after their brief encounter, which shatters the protective magic Alabaster cast to shield himself from Lamia. But with Claymore's help, Alabaster discovers an incantation that will bind Lamia to the Earth. However their mother, Hecate, steps in to intervene, saving both her children. According to Hecate, Lamia won't try attacking Alabaster again, knowing he could use that spell against her. Her fate is unknown.
In The Son of Magic, she is described as having glowing green eyes with serpentine slits. Her fingers shriveled and hardened and her nails turned into lizard-like claws when she extended her hand. She also has crocodile teeth.
- Latin: She is shown to speak and understand Latin when casting her spells.
- Mystiokinesis: As a daughter of Hecate, she is able to cast and manipulate magic. She is capable of performing powerful spells and magic.
- Cryokinesis (limited): When Lamia casts Gelu Semita spell, she is able to control and manipulate the cold to a limited degree.
- Pyrokinesis (limited): When Lamia casts the Templum Incendere spell, she can control and manipulate fire to a limited degree.
- Spell Crafting: As stated in The Demigod Diaries, Lamia is able to craft spells as when she crafted a spell to let every monster sense Demigods.
- Mist Control: As a daughter of Hecate, she is able to control the Mist. This ability means she is able to use the Mist to alter mortals' memories and perceptions, and she can also use this ability to also summon items and "Mistforms".
- She can create illusions.
- She can create false memories.
- She can make monsters invisible or have them be seen as something else.
- She can hide locations.
- She can summon Mistforms.
- She can hide people, beings, and objects.
- She can disguise people.
- She can influence the minds of mortals.
- She can teleport through the Mist.
- In Greek Mythology, after Hera murdered her children, Lamia became a serpentine monster and would eat children.
- Some myths say she was the daughter of Poseidon and Lybie.