Mercurial Slime
Huge Ooze
Hit Dice: 4d10+36 (58 hp)
Initiative: +1 (+1 dex)
Speed: 10 ft., fly 120 ft. (poor)
AC: 9 (–2 size, +1 Dex)
Attacks: Slam +3 melee
Damage: Slam 2d6+4 and 3d10 acid
Face/Reach: 20 ft. by 10 ft. /10 ft.
Special Attacks: Acid, engulf, scintillating Patterns
Special Qualities: Blindsight, immunities, ooze
Saves: Fort +5, Ref +4, Will +1
Abilities: Str 14, Dex 13, Con 19, Int —, Wis 1, Cha 20
Skills: Hide +1
Climate/Terrain: Any space
Organization: Solitary, Pair or Colonies (3–5)
Challenge Rating: ?
Treasure: None
Alignment: Always neutral
Advancement: 9–12 HD (Huge); 13–24 HD (Gargantuan)

    The mercurial slime is encountered in colonies that are no closer together than thirty feet. As such only one mercurial slime may attack a ship at a time.

    Mercurial slime is pervaded with a strong acid that works just like blood does for humans. It may be excreted so that it may dissolve nutrients and carry these to the individual cells of the organism. If the acid contacts living tissue it dissolves the skin dealing 3d10 damage in the process.
    Acid (Ex): The mercurial slime secretes a digestive acid that dissolves organic material and metal quickly. Any melee hit deals acid damage. The mercurial slime's acidic touch deals 50 points of damage per round to wood or metal objects. The opponent’s armor and clothing dissolve and become useless immediately unless they succeed at Reflex saves (DC 19). The acid can dissolve stone, dealing 20 points of damage per round of contact. A metal or wooden weapon that strikes a mercurial slime also dissolves immediately unless it succeeds at a Reflex save (DC 19).
    Blindsight (Ex): A mercurial slime's entire body is a primitive sensory organ that can ascertain prey by scent and vibration within 60 feet.
    Engulf (Ex): Although it moves slowly, a mercurial slime can simply mow down Large or smaller creatures as a standard action. It cannot make a slam attack during a round in which it engulfs. The mercurial slime merely has to move over the opponents, affecting as many as it can cover. Opponents can make opportunity attacks against the mercurial slime, but if they do so they are not entitled to a saving throw. Those who do not attempt opportunity attacks must succeed at a Reflex save (DC 21, if creating a gargantuan mercurial slime the DC is 24) or be engulfed; on a success, they are pushed back or aside (opponent’s choice) as the mercurial slime moves forward. Engulfed creatures are subject to the mercurial slime's acid, and are considered to be grappled and trapped within its body.
    Immunities (Ex): Mercurial slime are immune to cold, electricity and fire.
    Ooze: Immune to mind-influencing effects, poison, sleep, paralysis, stunning, and polymorphing. Not subject to critical hits.
    Scintillating Patterns (Ex): The silver surface of the mercurial slime catches starlight and reflects it in a lovely display of scintillating patterns of color, possible mesmerizing creatures viewing it. Roll 2d4 +1 per mercurial slime HD to determine the total number of HD affected. Creatures with the fewest HD are affected first; and, among creatures with equal HD, those who are closest to the mercurial slime are affected first. HD that is not sufficient to affect a creature is wasted. After this is determined, each creature makes Will save DC 10 + ½ mercurial slime's HD + mercurial slime's Charisma modifier to resist being mesmerized. Affected creatures gaze at the scintillating lights, heedless of all else, acting as if they are affected by hypnotism. Sightless creatures are not affected.
    Skills: Because the skin of the mercurial slime reflects the surrounding stars it gets a +8 bonus on Hide checks.

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©2002 Wizards of the Coast, Inc.

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Mercurial Slime, © 1991 Wizards of the Coast, Inc.
d20™ System, Conversion of Mercurial Slime ©2002, Flits3 and Mark Doolan
Original Source: Monstrous Compendium #9