Ye Olde Shoppe of Magicks – Viscous Vicious Slime

Viscous Vicious Slime

Large Ooze, Unaligned

Armor Class 7
Hit Points 97 (13d10 + 26)
Speed 20 ft., climb 20 ft.

STR 16 (+3) | DEX 5 (−3) |
CON 14 (+2) | INT 1 (−5) |
WIS 6 (−2) | CHA 1 (−5)

Saving Throws –
Skills –
Damage Vulnerability Acid enzyme produced by the Slime Eater
Damage Resistances acid, cold, fire, lightning
Damage Immunities poison; bludgeoning, piercing, and slashing from nonmagical weapons
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, prone
Senses blindsight 60 ft. (blind beyond this radius), passive Perception 8
Languages –
Challenge 5 (1,800 XP)
Proficiency Bonus +3

Traits

• Amorphous. The slime can move through a space as narrow as 1 inch wide without squeezing.
• Corrosive Body. Any creature that touches the slime or hits it with a melee attack while within 5 feet takes 9 (2d8) acid damage. Nonmagical weapons that strike the slime corrode: after dealing damage, the weapon takes a permanent and cumulative −1 penalty to damage rolls. If its penalty drops to −5, the weapon is destroyed. (Magical weapons are immune.)
• Divide. When reduced to 30 hit points or fewer, the slime splits into two smaller slimes (Medium, each with half its current HP).
• Split Reaction. When the slime takes slashing or lightning damage, it splits into two new slimes, each with half the original’s hit points.
• Acidic Hunger. The slime’s body constantly secretes an otherworldly digestive acid. Any creature that starts its turn grappled by the slime takes 2d8 acid damage, and any nonmagical weapon or piece of armor that strikes or touches the slime corrodes. After dealing damage to the slime with a nonmagical metal weapon, the weapon takes a −1 penalty to attack and damage rolls. If its penalty reaches −5, the weapon is dissolved. Nonmagical armor or shields touching the slime have their AC reduced by 1 per round of contact. At AC 10, the item melts into bubbling residue. The slime heals 5 hit points per item or weapon it completely dissolves — representing its feeding frenzy.
• Vile Intelligence. While seemingly mindless, this slime is a cunning mimic of its victims’ voices, habits, and even tactics. It can “remember” phrases and taunts spoken in its presence and uses them to lure the curious or separated. The slime has Advantage on Deception checks made to imitate sounds or voices it has heard. When in dim light or darkness, it can project illusory echoes (as the Minor Illusion cantrip, no concentration required) to mislead prey. Adventurers who fail a DC 14 Insight check may mistake its vocalizations for an ally in distress. Occasionally, its bubbling form coalesces into vague faces of past victims — hinting at absorbed memories.
• Engorged Consumption. When the slime has absorbed enough matter — typically 50 pounds of material, or after fully dissolving a Medium creature or the equivalent in weapons and gear — it spawns a new Viscous Vicious Slime. The newborn slime oozes forth from its parent’s mass, initially at half HP but growing to full strength within 1 hour. If multiple slimes feed together, they can combine their digested matter into a Spawning Pool, producing a Greater Viscous Slime (Large size, double HP, and stronger acid damage). Each spawning leaves behind a patch of residual goo known as “Slime Spawn Husk”, a faintly acidic, quivering residue that remains semi-alive for 1d4 hours — sometimes forming dangerous terrain.
• Predatory Hunger. The slime is drawn toward living creatures and will always prioritize the closest source of life force.

Actions

• Engulf. The slime moves up to its speed. While doing so, it can enter Large or smaller creatures’ spaces. A creature must make a DC 14 Dexterity saving throw.
  On a failed save, the slime enters the creature’s space and engulfs it; the creature takes 14 (4d6) acid damage and is restrained, unable to breathe. At the start of each of the slime’s turns, engulfed creatures take 14 (4d6) acid damage.
  A creature can escape by taking an action and succeeding on a DC 14 Strength check. On a successful check, the target escapes and enters the nearest unoccupied space. Success: Half damage, and the target moves to an unoccupied space within 5 feet of the cube. If there is no unoccupied space, the target fails the save instead.
• Pseudopod. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: 13 (2d8 + 3) bludgeoning damage plus 9 (2d8) acid damage.

Lair Feature
In areas where the slime lingers, the ground becomes slick and toxic. Any creature that starts its turn within 10 ft. of a slime must make a DC 13 Dexterity saving throw or fall prone and take 5 (2d4) acid damage.

Adventure Hook
The Viscous Vicious Slime is nearly impossible for normal weapons to destroy — a dungeon “gear check.”

The players must find and befriend the Slime-Eater, a tiny fey creature that looks like a cross between a squirrel, salamander, and axolotl. Only its appetite for the ooze makes the battle winnable.

⚖️ Balance: The slime (CR 5) is a mid-tier threat; the slime-eater (CR 1/4) is weak on its own, but its Slime Feast is the key to victory, making the encounter more about discovery and problem-solving than just combat..

Vicious Slime Vs Slime Eater

Ecology Sidebar: Predator and Prey

In the quiet groves and bogs of the fey-touched forest, a curious balance exists. The Vicious Viscous Slime devours all in its path, corroding roots and bones alike. But from the mossy burrows and hollow logs emerge their eternal counterbalance — the Forest Slime-Eaters, tiny fey beings that see oozes as both nourishment and sport.

Adventurers may stumble upon the aftermath of such duels: bubbling puddles of neutralized slime, glistening trails leading to burrows, and faint laughter echoing among the trees. The two species have battled since the dawn of the forest — one born of corruption, the other of cleansing nature magic.

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