Hebi-no-Onna
The Hebi-no-Onna (or Snake Woman) is a Dungeons & Dragons monster native to Rokushima Táiyoo and Sri Raji, the Oriental Adventures domains of the Ravenloft campaign setting. Possessing the forms of incredibly beautiful Asian or Indian women with writhing snakes for arms, they have incredible natural magical abilities, which in Advanced Dungeons & Dragons gives them the effective spellcasting prowess & capabilities of 14th level Enchanters, as well as hypnotic gazes and the ability to control serpents through their will alone.
These abilities are used to found cults who worship them as living gods, which the hebi-no-onna depend upon to secure their goals in life. They are consummate hedonists and relish physical pleasure, making the attaining of wealth and finery their driving goal.
An all-female race, hebi-no-onna reproduce by mating with intelligent, strong-willed, healthy, and handsome human, elf and half-elf men. They are very picky about the quality of their mates, striving to ensure that their lovers will provide the best possible traits for their daughters. Of course, such individuals are usually resistant to the hebi-no-onna's enchantments, forcing them to be captured and have their wills carefully broken so they will accede to the hebi-no-onna's desires. Because of the stringent requirements for a prospective mate, hebi-no-onna often devise plans to manipulate adventurers into discovering their cults and maneuver them into ill-planned attacks that are foiled by unforeseen traps. The most promising male adventurer is then chosen as the hebi-no-onna’s mate, while the others are conditioned to be guards or slaves.
And then, once they have finally fallen pregnant, a hebi-no-onna ritually sacrifices her lover in a great celebration before her cult.
Despite the obviously Japanese-sounding name, the hebi-no-onna is not, as far as /tg/ is aware, an actual Japanese yokai - it's something entirely made up for D&D. It may be a very drastically altered form of the Rokurokubi, the famous snake-necked woman.