Channeling my love of mind-controlling parasites.
H: Hegemonic ooze.
Lamplight illuminates a pinkish mass covering the floor, a number of humanoid copses scattered about. Someone cautiously pokes one of the bodies with a staff or spear. The 'corpse' opens its eyes and arises, lumbering toward the party. A number of others crawl to their feet, as well. Slimy tendrils stretch from their bodies back to the mass, and the bodies move in a strangely concerted manner.
A semi-intelligent ooze, perhaps originally meant as pest control, it was the product of an alchemist's lab or vivimancer's vat. Not a true ooze, it is a mass of neurons, sensing and questing for prey. It escaped and evolved, and rather than simply consuming, now co-opts some prey as weapons and sensory organs.
The pink leathery ooze extrudes tendrils, controlling 2d4 victim-puppets. Massive, the ooze may extend up to two tendrils with puppets up to 50 feet away from its central blob to reconnoiter away from its body, or to act as lures to draw prey towards itself and its victim-puppet appendages. If in need of new puppets, it will pummel or grapple intelligent prey to unconsciousness, and take over its nervous system and senses via neural connection through a tendril. The connection and hijacking of the prey's nervous system takes 6 turns (one hour). A victim may be rescued within 3 turns, but will lose 1d3 INT and CON.
HD: 9 (Ooze), 1 or 2 (puppets)
AC: 8/12 (Ooze), natural or worn AC (puppets)
Atk: Slam 1d10+1 (Ooze), 1d6 (puppets)
Move: 1 (Ooze), 3 (puppets)
Defenses: Ooze takes 1/2 damage from normal weapons, acid, and electricity. Puppets have similar resistances to mind-controlling spells (sleep, charm, etc.) as undead due to their networked nature. If a victim-puppet is severed from the slime, it will collapse, dead from the shock of separation.