Much of it resembles a grey tower, wide and ill-formed but no taller than a castle gatehouse. Feathers of many colours decorate its battlements and the roof is shingled raw meat and bones. It stands upon a pair of huge knobbly birdlike legs with deadly taloned feet and the ground shakes at its passing whilst flowers bloom in its wake, singing, weeping and sighing. 
In the Age of Sigmar, Zeyros used it to devastate a tourney being held by the Order of the Fly to decide the new Duke of Festerfane, one of the Blighted Duchies. Having abducted the Lady of Cankerwall, the Keep set a course for the depths of Bullawood, pursued by two score and ten knights of the Order and Carkus Gryme.
There it turned upon the knights and with Mordrek, slaughtered them and theirs armsmen. Despite the warnings by daemons in service to Zeyros, Carkus pressed on and approached the keep. As advised by the daemon Abigos, he blew upon a slughorn dangling from a tree to challenge the keeps master. 
Following the challenge, the keep carried Zeyros away.