Gelatinous Pudding, Elder (3.5e Creature)
From D&D Wiki
 Elder Gelatinous Cube
|Hit Dice:||14d10+154 (243 hp)|
|Speed:||20 ft, climb 20 ft|
|Armor Class:||1(-4 size, -5 dex), touch 1, flat-footed 1|
|Attack:||Slam+11 melee (2d6+4 plus 2d6 acid)|
|Full Attack:||Slam+11 melee (2d6+4 plus 2d6 acid)|
|Special Attacks:||Acid, Engulf, Paralysis|
|Special Qualities:||Ooze traits, Blindsight 60ft, Transparent, immune to electricity|
|Saves:||Fort +12, Ref -4, Will -4|
|Abilities:||Str 18, Dex 1, Con 32, Int -, Wis 1, Cha 1|
|Treasure:||1/10th coins, 50% goods(no nonmetal or nonstone, 50% items (no nonmetal or nonstone)|
You know those gelatin desserts your mom used to make as a kid?
A massive wall of quivering jelly slowly advances towards you. You charge it and roll a 1, causing you to trip and land headfirst into it.
An Elder Gelatinous Cube acts similar to a regular Gelatinous Cube but it's bigger.
Acid (Ex): An Elder Gelatinous Cube's acid only harms nonmetal and nonstone.
Engulf (Ex): An Elder Gelatinous Cube can simply mow down a Huge or smaller opponent by moving over them. An opponent can make an AoO if they want but they don't get a save. Those that didn't take the AoO are entitled to a DC 15 Reflex save. Those who fail are engulfed but those that save are pushed back or aside (opponents choice). Those inside are considered grappled and trapped and are subject to the Elder Gelatinous Cube's acid and paralysis.
Paralysis (Ex): An Elder Gelatinous cube excretes a potent anesthetic slime. Those hit by a melee attack or engulfed are subject to a DC 28 Fortitude save or become paralyzed for 4d6 rounds. The Elder Gelatinous Cube can automatically engulf a paralyzed opponent.
Transparent: Elder Gelatinous Cubes are hard to see even under ideal conditions. It takes a DC 13 spot check to prevent from walking into it. Those that do are automatically engulfed.