A group of shadow aligned creatures from the Shadow Plane who assaulted First Landing during the First Landing Spooky Costume Anniversary Party. Led by Ancalag the Devourer.
"I will avail to you what I know of the Shalak'ui. They are an opportunistic conglomerate of mercenaries and slave-soldiers led by the insidious owbs and an alliance of power-hungry lords of the Plane of Shadow. What First Landing faced down was their attempt at invading the Material Plane - had they succeeded, they could have used this Portal to bring the full might of their masters upon you and your world. But they have been prevented from doing so, and in so doing we dealt a grievous blow to their forces and for that I, and every other goodhearted denizen of the Plane of Shadow, thank you."
- The Mysterious Stranger