This thick green blob lays on top of the water, devouring everything it touches.
AC 6, touch 6, flat-footed 6 (-2 Dex, -2 size)
Str 26, Dex 7, Con 29, Int 5, Wis 8, Cha 1
The bog scum secretes a digestive acid that dissolves organic material and metal quickly, but does not affect stone. Each time a creature suffers damage from a bog scum’s acid, the creature’s clothing and armor takes an equal amount of damage from the acid. A DC 25 Reflex save prevents damage to clothing and armor. A metal or wooden weapon that strikes the bog scum takes 2d8 acid damage unless the weapon’s wielder succeeds on a DC 25 Reflex save. If the bog scum remains in contact with a wooden or metal object for 1 full round, it inflicts 25 points of acid damage (no save) to the object.
Environment warm or temperate swamps
A bog scum is a creeping layer of thick, green translucent ooze that lies atop the surface of rancid water or crawls along the ground toward prey. Though barely-intelligent, bog scum is highly effective at grabbing and digesting its prey. It can sense when living creatures get close and will spend hours crawling toward stationary, warm prey. Travelers report waking to a companion enveloped by bog scum, murdered by virtue of having slept closest to the water.
The bog scum attacks by forming itself up into a 12 ft. tall ball of green plasm and slamming part of its translucent body onto a nearby creature. The scum sticks to its prey and envelopes creatures, both suffocating and digesting its meal very slowly.
Book of Beasts: Monsters of the River Nations, copyright 2010 Jon Brazer Enterprises; Author Steven Helt.