Dabus

Dabus
Among the bustling throngs of Sigil's streets float gray-skinned, vaguely humanlike figures with curled horns. Where they travel, cracks in the mortar seal shut, stray bricks float back into place, and ruined city blocks are restored. These are dabus, the silent caretakers of Sigil and loyal servants of the Lady of Pain.
Dabus patrol the City of Doors to maintain public buildings, portals, and utilities. They use their innate ability to manipulate Sigil's infrastructure not only to effect repairs but also to combat individuals who disrupt the city's operations or violate the Lady's edicts, hurling bricks at troublemakers and subduing them by causing the streets to sprout grasping cobblestone hands.
When dabus communicate, rather than speaking or signing words, they create esoteric illusory images and symbols in front of themselves. Scholars have yet to determine the origin of dabus's difficult-to-comprehend rebuses, though some speculate their etymology predates Sigil itself.