Morrslieb is the dark moon of the warhammer world. Known to be an ill omen and sign of chaos it has been known to drive people mad with visions and nightmares of hell and daemons, endless incessant voices giving dark promises and temptations. And even known to cause the body to warp and mutation for prolonged exposure.

One night it appeared behind Luna's moon, and for the first time Equestria knew true chaos.