Thurstle Island: Oozes of the Undercity

Jared Murphy (King328)

In my Thurstle Island campaign, oozes in their many varieties are the corrupted remnants of the Ancients' servitors. Their minds were poisoned by the malign influence of the Twisted Wyrm, buried nearby. This is not an original idea. It is drawn directly from Lovecraft: 

They had always been controlled through the hypnotic suggestion of the Old Ones, and had modelled their tough plasticity into various useful temporary limbs and organs; but now their self-modelling powers were sometimes exercised independently, and in various imitative forms implanted by past suggestion. They had, it seems, developed a semi-stable brain whose separate and occasionally stubborn volition echoed the will of the Old Ones without always obeying it.

The oozes, slimes and jellies overthrew their creators but lacked the sophistication to form a society of their own. Effectively immortal, they have roamed the decaying city for centuries, some are maddened and consumed with hatred, others are merely bewildered and frustrated.

I don't want oozes to be just another sludgy slurry of hit points. Consequently, ooze-type creatures take no damage from weapon attacks. Deciphering their other vulnerabilities is what makes them fun. Each type of ooze is it's own mini-game.

Oozes do share a few things in common: 

• They hate the cold. It slows their movements and their minds. Even minor chilling magics will dramatically reduce their mobility and power. Freezing an ooze solid then shattering it, is one of the few methods that works on nearly every type.
• They are often disrupted by admixture. Dirt, salt, water. It depends on the variety of ooze what bothers them most.
• They can climb vertical pipes and shafts if the concentration of their bulk is large enough to fill the space. I.e. a 10' Jelly Cube can ascend an 8' wide shaft but not a 15' diameter pipe.
• They can squeeze through cracks and small spaces though the process is usually slow. 
• They cannot cross a grate without dropping through.

Fortunately for the players, rods of ooze control are not too uncommon in the Ancient City.

Typology: 

Monstrous Compendium Volume 1, 1989 TSR Inc.

Jelly Cube

The most common and least advanced of the oozes. They were the Roombas of the city, tasked with cleaning surfaces and removing waste. Too stupid to participate in the rebellion they blindly continue their assigned tasks. Most of the ones still around are damaged or malfunctioning in some way. 

• Invisible until they have absorbed material and begun to digest it. A handful of dirt will make them visible for seconds, absorbing a human body will take several minutes.
• Only dissolve organic materials. Weapons, armor etc. remain in the cube until they are deposited in a waste disposal area.
• Their primary sense is analogous to smell and they'll detect and move toward organic material within 10' of them.
• Invulnerable to acid and poison, but fire, lightening and other energy attacks can damage them.
• Salt melts a cube like a slug. They won't cross a line of salt. 
• They can't hold their form in water. A firehouse could cause significant damage. 
• If destroyed, melt into a dangerous pool of acid.

Darkest Dungeon

Cracked Cubes: 

1. Hoarder: Never drops the inorganic material that it collects. Consequently, easy to spot and full of weapons, armor and metal tools.
2. Wallflower: Only moves along walls. Cannot move into the center of a big room.
3. Malign Intelligence: Somehow has become smart and will craftily stalk any living creature it detects. Can follow your stink trail.
4. Collector: Seeks out crystals and can somehow sense them through walls at a significant distance. Likely contains several crystals of various types.
5. Gullible: If you can find a way to psychically communicate, it will do whatever it's told to. 
6. Jelly Skelly: If a cube's acidic potency fades, it can lose the ability to fully dissolve bone. As it's deterioration progress, it desiccates and forms a rubbery layer over the subsumed bones. My players have faced these before (in TotSK) and will be both delighted and irritated to see them again.

Gray Putty

Dumb but sneaky ambush predators. When still, they look like damp rock. They cannot move quickly so they hide and wait for prey to approach them, then grab on and begin pummeling. Once reduced to a paste, the target is absorbed.

• Attack by lashing out a pseudopod, like being slapped with a sock of wet concrete.
• Instantly corrode any metal they come in contact with. They'll punch through your armor like it isn't there.
• Despite their moist appearance, highly water soluble. 
• Can be baked into a solid with enough heat. 

Green Slime

A malevolent liquid monster. Rapid digestion and virulent reproduction makes them a threat that easily gets out of hand. They hide in small spaces or on ceilings then spurt out to metabolize prey. 

• Every hit point of damage they deal adds a hit point to their total. 
• The more HP they have the more damage they do. 
• When they get big enough, they split. 
• Highly vulnerable to fire.

Slime Time!

Recycler (Silver Slime)

Looking like liquid mercury and acting like an autonomous 3D printer they slither through the dark seeking metals to reshape. They were sensitive and have all gone quite crazy, working on strange projects or futility trying to complete their last orders. 

• Can sense any nearby metal, even through walls and will move quickly to process it.
• Will quickly dissolve and absorb metal that they touch. 
• Usually don't harm living things, beyond taking their metal.
• If cornered or controlled could be quite useful.
• Unlike most oozes, utterly wrecked by acid.

What do they do with all that metal?

1. Manufactor: Will leave behind a trail of: 1. Scissors, 2. Caltrops, 3. Wire, 4. Spoons.
2. Constructor: Build a strange structure somewhere nearby.
3. Fencer: Block off random halls and doorways with barbed wire barricades.
4. Slasher. Turn itself into a seething mass of blades and spikes. Kill any living thing. 

Black Pudding

A fast moving (by ooze standards) corrosive tar-like mass. Instinctively belligerent. 

• Deals acid damage to both equipment and creatures. 
• Super sticky. Anything that touches it can be adhered. 
• May melt through walls or floors in pursuit of prey.
• Can move over difficult surfaces including walls and ceilings
• Can split into multiple pieces which will work together to defeat prey.
• Highly resistant to psychic control.
• Destroyed by salt and solvents. Retreats from bright light.
• Burns like tar. While on fire they move extra fast and they'll last awhile.
• Can't stick to, can be cut by, glass. If cut into small enough pieces, it will die.

Pixie Bledsaw, The Thieves of Fortress Badabaskor, Judges Guild, 1978

Shoggoth

It was a terrible, indescribable thing vaster than any subway train—a shapeless congeries of protoplasmic bubbles, faintly self-luminous, and with myriads of temporary eyes forming and un-forming as pustules of greenish light all over the tunnel-filling front that bore down upon us, crushing the frantic penguins and slithering over the glistening floor that it and its kind had swept so evilly free of all litter.

— H. P. Lovecraft, At the Mountains of Madness

• As big and threatening as a dragon. The worst possible boss-ooze.
• Capable of generating advanced organs as needed and nearly indestructible.
• To be fled, not fought, unless extraordinary weapons are available.
• I'm still working out the mechanics to make these as awful as they need to be.