Near-undetectable shapeshifting ambush predators that grow limitlessly in power and intelligence with age — flesh-eaters and one of the dungeon's deadliest sapient factions.
Shadow Mimics are a especially dangerous branch of the dungeon's many mimic types, revealed when the entire remodeled Desperado Club casino — tables, slot machines, chairs, even a guard — springs to life as a swarm of some fifty mimics (levels 25-120, most around 80) with huge toothed mouths, ambushing Carl's crew. Per the AI and Mordecai, Shadow Mimics are the natural counter to their archenemies the changeling principals, and are unique in growing in intelligence, strength, and power without limit as they age — so much so that wise floor designers leave them alone, and they are 'especially prone to ideation breaking' (going self-aware). They are almost impossible to detect: they can impersonate objects or crawlers, and the system labels a disguised mimic as the real thing until it's exposed, making safe-words and daily quizzing the only defense (Donut's magic-sight works only on those mimicking objects, not people).
Flesh-eaters by nature, they kill and consume their victims (the Mitch mimic ate the real Mitch, a Wall Rat) and, when slain, collapse into thin, armless gray tentacled forms like changelings do. As a group the loose Shadow Mimics are one of the AI's 'Big Six' powers vying to control or escape the dungeon.
Shapeshifters that hold an object's or person's form until they attack, then bulge into toothed blobs; slain, they melt to thin armless gray bodies with tentacle-like protrusions.
Near-undetectable, ever-growing shapeshifting ambush predators — a top-tier sapient threat among the dungeon's Big Six.