Tirawen

A mindless elemental life-force that gathers wherever stray magic seeps into a still pool of mud and concentrates there. When intruders disturb its water, the sludge draws itself together and rises as a squat, four-foot humanoid of dirty brown to tar-black muck, with thick clumsy fingers and eyes like pits of black shadow. Its legs stay rooted in the pool. It cannot speak or think, it exists only to drown anything that enters its water. While sunk and dormant it is untouchable by weapons; roused and standing, it can be cut down. Several share a single pool, making an unwary crossing a sudden, smothering ambush rather than a fair fight.

Behavior

Lies dormant and spread across the pool bottom, immune to weapons until it rises.
Senses any creature entering its water and surges up the following moment.
Hurls hardening mud to clog and slow a victim before closing.
Flings its own substance at a trapped foe, destroying itself to immobilize them.
Never leaves its pool; sinks back to wait if prey flees the water.

Abilities

Mud Hurl. Throws gobbets of mud that harden on impact and slow the target.
Smothering Lunge. Sacrifices its body to coat and pin a slowed victim, suffocating them over a short time.
Dormant Submersion. While sunk in the pool it cannot be harmed by any weapon.
Spell-Fed. Immune to poison and mind-affecting effects; drawn to and sustained by ambient magic.

Drops & Crafting

Dweomer-rich mud (alchemical reagent)
Fine river clay (pottery and moulds)
Bones and wood scraps absorbed from past victims
Magic-tainted silt prized by enchanters