A rare, cultish sect of collection-obsessed changelings driven to touch and hoard every rare creature-form — secretly running Hump Town's guard.
The Changeling Principals are a rare, old sect of changeling culture Mordecai half-remembers — cultish and power-hungry (less apocalyptic than the third floor's city elves), sometimes granted special powers, and consumed by the need to complete their "library" of touchable forms, obsessing over the rare creatures they still lack. Carl discovers they've infiltrated Hump Town's Waster Patrol and hostage operation, torturing Wynne to add the flaming pterodactyl Quetzalcoatlus to their collection. Killed while untransformed, their glowing brains make a potion; knocking them out can force them to revert.
Changelings in disguise as camels or others; in true form, small faceless humanoids with sapphire-glowing heads.
A collection-obsessed changeling cult secretly controlling the town's hostage scheme.