Malcanthet is the queen of succubi and lilitu, although both races serve other demon lords and ladies as well. She resembles a beautiful human woman with wings, horns, and a snakelike tail. She has a vicious rivalry with Graz'zt. Red Shroud is one of her many daughters.
She uses succubi, incubi, and similar creatures as servants, so it's
impossible to not describe her as a pimp (or madame, technically), but
she's subtle about it. Her servants (demonic, petitioner, and mortal)
think of themselves as hedonists and libertines, not as desperate souls
doing a job they don't really want to do.
She preys on lustful and hedonistic souls, bending their desire into
something corrupt - and she also preys on those already corrupt,
teaching them the mysteries of desire. The text doesn't mention any
grand plan to change lust in general - she seems content to use lust as
it is as a tool. She does gradually change the lust of an individual
into something horrifying.
She does less subtle things too - she tortures and murders. And below
her servants are countless slaves who aren't remotely hedonistic - they
perform manual labor in her vineyards and fields.
Dungeon #112, page 48, and #124, page 95
Fiendish Codex I: Hordes of the Abyss
Dragon #353 - "Demonomicon of Iggwilv: Malcanthet" by James Jacobs