Succubus (Suk-u-bus)

A succubus (pronounced: /ˈsʌkjuːbʌs/ SUK-yoo-bus pl: succubi) was once known to be a type of demon, a beautiful lesser breed of tanar'ri from the Infinite Layers of the Abyss. They existed to seduce and tempt mortals and ultimately slay them and take their life energy back to the Abyss. In the 15th century DR, circa 1479 DR, they were instead considered to be a form of devil of the Nine Hells, and they tempted mortals into villainy. However, after the Second Sundering of 1487 DR, they were known as simply fiends, found across all the Lower Planes and serving all kinds of evil.
The male counterpart of this creature was called an incubus (pronounced: /ˈɪŋkjuːbʌs/ INK-yoo-bus). Legend held that incubi and succubi were wholly separate sexes, and the males were significantly rarer than the female of their kind. In fact, with their shapechanging powers, incubi and succubi could both change their sex with ease, though most had a preference for one or the other.