Ulgu is the Realm of Shadows, in the Eight Realms. Ulgu has thirteen regions all covered and shrouded in with illusion and menace. Secrets and riddles are whispered throughout. The Terrorgheist's ancestors may have come from Ulgu to Shyish, where they were enslaved by Nagash.
- Penumbral Sea: Kingdoms of Flesh-eater Mordants floated in the Penumbral Sea.
- Quicksilver Swamp: Scyla Anfingrimm hunted and killed the ur-hydra Gorgahul here.
- Spyrglass Warrens: The Spyrglass Warrens were destroyed by Chaos Daemons. Urglom only survived by feeding on his kin.
- Umbral Deeps: The Umbral Deeps was one of the few locations where Archaon was repelled during the Age of Chaos.
- The Bridge of Sorrows: This Realmgate connected Ulgu and Shyish. After it was opened and corrupted by Chaos, the Seraphon intervened.
- Penumbral Gate: The Arcway of Ulgu. The fate of this Realmgate is currently a mystery, as all forces sent there do not return.
- 1: Warhammer: Age of Sigmar Primer
- 2: Death Battletome: Flesh-eater Courts
- 3: Chaos Battletome: Khorne Bloodbound
- 4: Chaos Battletome: Everchosen
- 5: Order Battletome: Seraphon
- 6: The Realmgate Wars: All-gates
- 7: Order Battletome: Fyreslayers