Goop Ghoul

A goop ghoul is a clear, amoeba-like blob related to oozes such as the black pudding and gray ooze. On its own it can barely crawl. When it slides over an ordinary skeleton (not an undead one), it wraps the bones like muscle and sinew and uses them to walk at a movement rate of 12. Most are met this way, and there is an 80% chance one will be taken for an undead skeleton or a decayed zombie, its stretched body looking like rotten tissue.

Bones of any biped or quadruped from about 3 to 9 feet tall will serve; outside that range it is either too cramped or stretched too thin. Movement stays 12 regardless. Rarely it will bind itself to sturdy rodlike objects instead, managing half speed. A party might even see a bundle of swords hobbling toward them, though a real skeleton is always its first choice. Attaching to a frame well enough to work it takes one round.

Riding a skeleton, the goop ghoul can wield simple hand weapons but cannot use shields or metal armor. Its touch paralyzes for 4d4 rounds unless the target saves vs. paralysis. It then takes one round to cover the helpless victim and dissolves flesh at 1d8 hp per round. Its acid is too weak in small amounts to hurt anyone not fully engulfed, so it has no acid attack in ordinary melee. A victim who recovers before being consumed can shake it off and run, and is immune to its paralysis for a full day afterward.

Feeding swells it. By the time a skeleton is stripped clean, the goop has doubled in size and splits into two normal goop ghouls in one round. Whichever is closer usually claims the fresh bones. An ogre provides enough flesh to split into three.

It is immune to electricity and takes half damage from cold, but fire and intense heat deal double damage, and it avoids both. Flame applied to one that is feeding drives it off its victim. So do heal and cure disease, though they do not harm it.

Because it is not undead, priests cannot turn it. It can, however, ride an animated undead skeleton, with no say in where it goes. Turning that skeleton just frees the goop to look for new transportation, quite possibly the priest. A creature the goop has slain and digested can only be raised with a wish, though its bones can still be animated with animate dead.

Goop ghouls live only underground, since sunlight gradually dries their skins. They are solitary, with no social structure; a group usually means one has just divided.

They have no grasp of money and keep no treasure. Metal is beyond their acid, and metal armor weighs too much for them, so they prefer targets without it. When one takes over a new skeleton it wants only the bones and perhaps a weapon, leaving valuables behind. They are rare enough to matter little unless many gather. Predatory but patient, they can go days without eating and will happily scavenge.