Ooze Cube. The cube takes up its entire space. Other creatures can enter the space, but a creature that does so is subjected to the cube's Engulf and has disadvantage on the saving throw.
Creatures inside the cube can be seen but have total cover.
A creature within 5 feet of the cube can take an action to pull a creature or object out of the cube. Doing so requires a successful DC 12 Strength check, and the creature making the attempt takes 10 (3d6) acid damage.
The cube can hold only one Large creature or up to four Medium or smaller creatures inside it at a time.
Transparent. Even when the cube is in plain sight, it takes a successful DC 15 Wisdom (Perception) check to spot a cube that has neither moved nor attacked. A creature that tries to enter the cube's space while unaware of the cube is surprised by the cube.
Pseudopod. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 10 (3d6) acid damage.
Engulf. The cube moves up to its speed. While doing so, it can enter Large or smaller creatures' spaces. Whenever the cube enters a creature's space, the creature must make a DC 12 Dexterity saving throw.
On a successful save, the creature can choose to be pushed 5 feet back or to the side of the cube. A creature that chooses not to be pushed suffers the consequences of a failed saving throw.
On a failed save, the cube enters the creature's space, and the creature takes 10 (3d6) acid damage and is engulfed. The engulfed creature can't breathe, is restrained, and takes 21 (6d6) acid damage at the start of each of the cube's turns. When the cube moves, the engulfed creature moves with it.
An engulfed creature can try to escape by taking an action to make a DC 12 Strength check. On a success, the creature escapes and enters a space of its choice within 5 feet of the cube.
As a DM, Cube in water is one of my favorite traps: greed. "The party comes across a narrow 15-foot-deep pool of clean, clear water, perfect for drinking. Above the pool hangs a luminescent plant that emits a soft glow. At the bottom of the pool glitters a smattering of coins and a large gem, but only one gem..."
A creature diving for the gem will enter the Cube willingly, meaning they get disadvantage on their Dex saving throw once they realize only the top 5' is water. Usually, that means one party member is stuck underwater, restrained inside the Cube, and starting to be dissolved. Fire is the best way to fight a slime, but with 5' of water as a shield, this becomes a difficult trap to get out of.
i just called it the jello cube
Would be nice if something besides a saving throw could have an impact on these lobs. Actions by others of the party could take to aid their entrap companion. Lie maybe heat magic or potion to counter acid the acid. Just thinking like an artificer, herbalist healer gnome.
My favorite character in Dungeons & Dragons Honor Among Thieves!!!
Not covered RAW, but it wouldn't make any sense to be able to breath inside of acidic jello
What happens if there is a gelatinous cube inside of another gelatinous cube????
the amount of these truckers i have fought and almost died to are endless i hate these!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
my party pulled out a chest out of one of those.
Just love these things!
(Is that weird)