Lamias are virtually the same as ordinary witches. The only difference is their appearance and maybe their strength. There are two categories of lamia witches: The domestic and the feral. Lamia witches shun sunlight and at night, they drink the blood of men.
Domestic Lamias - are lamia witches who have spent some time with humans, thus taking the appearance of a normal if not beautiful woman.
Feral Lamias - are lamia witches who are savage and don't have the appearance of a woman.
Lamias can also be classified under two different types: The ground and sky lamias.
Ground Lamias - are lamias who scuttle about the ground on her four legs.
Sky Lamias - are lamias who have wings and can fly short distances with these.they are also known as veanger
One way to separate them from other women when they are in their domestic state is to watch out for a line of green scales that runs down their spine.
The First Lamia
The first of the Lamias was a beautiful and powerful enchantress who was in love with Zeus. Lamia bore Zeus children, however, when Zeus's wife, Hera, discovered this, she slew all but one of them. Lamia was driven inane with grief and began to kill children wherever she found them. Eventually the gods punished her by transforming her into a serpentine, scaly humanoid creature with a beautiful head and shoulders. She preyed on young men, luring them with her upper body beauty and then wrapped her lower body around him like a Boa Constrictor would and drain his blood. Later, Lamia bore a spider-like creature called Chaemog female triplets, the first lamia witches. After a quarrel with their mother on their thirteenth birthday, the triplets tore her to pieces and fed her to a boar.
However, in book 6, Mam claims she is the first lamia, meaning that the information on Lamia's demise found in The Spook's Bestiary could be a misinterpretation or legend that has become a false fact.