Slaanesh is the Chaos God of Lust, Excess, Pleasure, Perfection and Hedonism in the fictional universes of Warhammer and Warhammer 40,000. Slaanesh typically appears in a form which is a woman on the right side and a man on the left with two sets of devilish horns growing from its head. It can however assume any form; male, female, hermaphrodite or asexual, but prefers male bodies. Its sacred number is six. It is known as the Prince of Chaos.

In Warhammer 40k Slaanesh was born during the time the Eldar call The Fall, from the decadence of the Eldar in the Warp. The Birthcry of Slaanesh created the Eye of Terror and slew most Eldar (and their gods except for Khaine who was dispursed into many pieces and the Harlequin), except those very far away from the Eldar Worlds.