She is adoptive sister to Elena the Fair, a lawful good sorceress of whom she is jealous, though she wishes no harm upon her. Iggwilv is the adopted daughter of Baba Yaga, from whom she first learned magic. Iggwilv accepts Fiend's Embrace from Graz'zt. She also collects mold and fungi, including sentient species. She has a preference for the use of demons as servants. She is somewhat vain, materialistic and desires wealth, collecting treasure and magic items in particular. She plotted careful revenge against the Circle of Eight after they foiled one of her plans, but quickly lost interest after her revenge failed. While she makes an exceptionally powerful ally, she also has a reputation for treachery. As Witch Queen of Perrenland, she subjected its people to such a reign of terror that, a century later, mothers still invoked Iggwilv's name to frighten disobedient children. Iggwilv is capricious, wicked, and highly ambitious. Circa 597 CY, during her planes, she wore an iconic revealing dark green dress along with the demonskin artifact cloak Fiend's Embrace. She is sometimes seen with a tattoo or mark beneath her right eye representing a three-forked line, known in the Flanaess as an inverted form of a rune representing evil magic, although its purpose is unknown. As Tasha, she is sometimes depicted wearing an iconic witch's outfit with dark robes and a tall pointed hat, as well as a variety of other clothing. In another, as Iggwilv circa 585 CY, she is a thin woman with golden skin, with eyes resembling black pools, and wears a dark gray robed hood. In her guise as Natasha, she is a tall, slim human woman with long black hair and alabaster skin. While she favors beautiful appearance, it is believed that the crone is her true form, although none live who have ever seen it.

Iggwilv famously appears in a range of guises, from a bald, hideous crone to a beautiful woman.

Demonomicon book of demons