Lamia

When rage and despair at the gods' misdeeds consume a mortal mind, a lamia comes into being. Most lamias in Theros are Nyxborn (described earlier in this chapter), owing their existence to their own twisted imagination, which has changed their physical Nature to reflect their internal self. Lamias have wildly varying physical forms, ranging from a feline shape similar to the lamia in the Monster Manual to a more serpentine form similar to a Yuan-ti. In each case, the lamia's body reflects the creature's corrupted instincts and predatory Nature.
A lamia has a beautiful Humanoid upper body that merges into a powerful four-legged leonine form. Its Vicious black claws speak to its predatory Nature, as does its hunger for torture and Humanoid flesh. Tyrants of Pleasure. Lamias adorn their crumbling havens with finery stolen from passing caravans, then use magic to further accentuate their lairs, masking decay with Illusion. A lair’s breathtaking gardens, finely decorated apartments, and numerous Slaves seem at odds with its remoteness and state of ruin.
Using its intoxicating touch, a lamia weakens the minds of its enemies, making them more susceptible to its Enchantment Spells and turning them into its Slaves. Those it beguiles with geas Spells are pitted against each other in elaborate Contests for the lamia’s amusement.
Vain Predators. Always anxious to gain more Wealth and Slaves, a lamia uses a pool of water or a mirror in conjunction with a Scrying spell to view its domain. A lamia uses this power to watch over trade routes and nearby Settlements, or to seek out Objects and creatures it fancies.
Lamias are particularly fond of seeking out Adventurers with pure hearts to seduce and corrupt to evil, savoring the destruction of their virtue. They use their magic to lure potential victims to their lairs, relying on Illusion and their thralls to Capture hapless foes. Lamias prize beauty and Strength above all else, however. Any prisoner that falls short of their esteem becomes the main course in a horrible feast, or is set free to die while wandering the wastes.
As long as they have Slaves to face their enemies, lamias fight from the fringes, beguiling foes with magic if they can. A lamia pressed into melee never stays there for long, shredding flesh with claw and Dagger before springing away to safety.