# Gelatinous Cube - Creature: Ooze - Date: 1975 - Canonical: https://www.lanternhall.org/bestiary/gelatinous-cube/ > A perfectly transparent ten-foot block of acidic jelly that slides down dungeon corridors digesting everything organic: the monster that only makes sense in a D&D dungeon. **Why it matters:** The gelatinous cube is a joke on the dungeon's own geometry, a creature shaped exactly to fill the standard ten-foot corridor, and it became a symbol of the logic and humor peculiar to D&D. ## Quick answers **Where does the Gelatinous Cube come from?** Original D&D monster by Gary Gygax, introduced in the Greyhawk supplement (1975); descended from the game's blob-inspired slimes and jellies. **When did the Gelatinous Cube first appear?** 1975, in Supplement I: Greyhawk (TSR). **How did the Gelatinous Cube get into games?** Key appearances: Original D&D boxed set (1974), Supplement I: Greyhawk (TSR) (1975), AD&D Monster Manual (1977), NetHack (1987) and D&D 5th Edition Monster Manual (2014). **Why is the Gelatinous Cube significant?** The gelatinous cube is a joke on the dungeon's own geometry, a creature shaped exactly to fill the standard ten-foot corridor, and it became a symbol of the logic and humor peculiar to D&D. ## Origins The gelatinous cube is the product of a particular idea of the underworld. Early [Dungeons & Dragons](https://www.lanternhall.org/works/original-dungeons-and-dragons/) was played on graph paper, and its dungeons were built from corridors ten feet wide, with square rooms joined by doors. The first boxed set of 1974 already had scavengers suited to that space: gray ooze, ochre jelly, black pudding and green slime. These amorphous dissolving monsters are usually traced to the 1958 film *The Blob* and, beyond it, to the single-celled amoebae that engulf their food. In 1975 [Gary Gygax](https://www.lanternhall.org/makers/gary-gygax/) took the idea to its logical end. If something had to keep the corridors clean, it could be shaped exactly like a corridor. The result appeared in *Supplement I: Greyhawk* (1975), the rules booklet Gygax wrote with Rob Kuntz (see [World of Greyhawk](https://www.lanternhall.org/works/world-of-greyhawk/)): a transparent cube of jelly ten feet on a side that slides through the passages absorbing anything organic. Bones, coins and steel pass through its body undigested and are left behind. It needs no legend to explain it, because it was designed for the dungeon itself. Writers on the game call it the dungeon's "clean-up crew," which is also a sly explanation of why the corridors are not full of dead adventurers. ## Into the dungeon The cube is dangerous because it is hard to see. In a torchlit passage an inattentive party can walk straight into it. Its touch paralyzes, and anyone caught inside is slowly dissolved. In the *Monster Manual* of 1977 it joined the core bestiary of [Advanced Dungeons & Dragons](https://www.lanternhall.org/works/advanced-dungeons-and-dragons/), and it was a regular in [Basic D&D](https://www.lanternhall.org/works/dnd-basic-set/) from the 1977 Holmes set to the *Rules Cyclopedia* of 1991. *Dragon* magazine (see [The Strategic Review & Dragon](https://www.lanternhall.org/culture/dragon-magazine/)) examined it in issue #124 (August 1987). Later rulebooks grouped it with the other oozes: the "ooze/slime/jelly" entries of the [second edition](https://www.lanternhall.org/works/dnd-2nd-edition/) *Monstrous Compendium*, the ooze chapters of [third](https://www.lanternhall.org/works/dnd-3rd-edition/) and [fourth](https://www.lanternhall.org/works/dnd-4th-edition/) editions, and the [fifth edition](https://www.lanternhall.org/works/dnd-5th-edition/) *Monster Manual* (2014). There its art was redesigned, one history notes, "to entice more Dungeon Master use": the cube is shown full of the weapons, bones and loot of earlier victims. It spread from the tabletop to screens. The cube lives in the [Roguelikes](https://www.lanternhall.org/atlas/roguelike/) [NetHack](https://www.lanternhall.org/works/nethack/) and in *Baldur's Gate: Dark Alliance* (2001). Gelatinous cubes also turn up in cartoons, such as Pendleton Ward's *Adventure Time* and a 2017 episode of *The Simpsons*. Pixar's *Onward* (2020) thanked [Wizards of the Coast](https://www.lanternhall.org/houses/wizards-of-the-coast/) in its credits for the use of the cube and the [Beholder](https://www.lanternhall.org/bestiary/beholder/). In *[Dungeons & Dragons: Honor Among Thieves](https://www.lanternhall.org/works/honor-among-thieves/)* (2023) the heroes flee one through the Underdark, and Hasbro sold a six-inch-scale action figure of it with the film. ## Variations The cube is the most famous member of a family of D&D oozes: green slime, which turns flesh into more slime; the metal-dissolving black pudding; the gray ooze; and the ochre jelly. Japanese RPGs made the cheerful blob a mascot instead. Its relative is the [Slime](https://www.lanternhall.org/bestiary/slime/) of *[Dragon Quest](https://www.lanternhall.org/works/dragon-quest/)*, a small, smiling teardrop and not a corridor-sized killer. [Paizo](https://www.lanternhall.org/houses/paizo/) covered the cube in detail in *Dungeon Denizens Revisited* (2009) for [Pathfinder](https://www.lanternhall.org/works/pathfinder-rpg/). Home campaigns have added many more, and the cube shares a trade with the [Mimic](https://www.lanternhall.org/bestiary/mimic/): both are traps that look like part of the dungeon. The joke has lasted because it is also true of the whole [Dungeon crawl](https://www.lanternhall.org/lexicon/dungeon-crawl/). The dungeon was built for play, not realism, and the gelatinous cube is its most honest creature: a monster that fits exactly the space the game drew for it. ## Migration - 1958: The Blob (film) — A creeping, engulfing mass from space; historians of D&D's monsters trace the game's oozes and slimes to it. - 1974: Original D&D boxed set — Monsters & Treasure stocks the dungeon with gray ooze, ochre jelly, black pudding and green slime. - 1975: Supplement I: Greyhawk (TSR) — The gelatinous cube is born: a ten-foot, transparent block that sweeps corridors clean of anything organic. - 1977: AD&D Monster Manual — The cube joins the first hardcover bestiary; Dragon #124 (1987) later explores it further. - 1987: NetHack — The cube engulfs and paralyzes in the roguelike tradition. - 2014: D&D 5th Edition Monster Manual — A redesigned cube, stuffed with half-digested adventurers' gear, invites Dungeon Masters to use it more. - 2023: Dungeons & Dragons: Honor Among Thieves — The heroes escape a gelatinous cube in the Underdark; Hasbro sells a six-inch action figure of it. ## Facts - The gelatinous cube is an original Gary Gygax invention, first published in Supplement I: Greyhawk (1975). - It measures exactly ten feet on a side, the width of the standard corridor on early D&D graph-paper maps. - Commentators describe it as the dungeon's "clean-up crew," explaining why corridors are not littered with the remains of dead adventurers. - Its transparency is its weapon: in a dim corridor, only an alert character notices it before being engulfed. - Pixar's Onward (2020) thanks Wizards of the Coast in its credits for letting it use the gelatinous cube and the beholder. - A 2017 episode of The Simpsons, "The Serfsons," features a gelatinous cube. ## Sources and further reading - [Wikipedia](https://en.wikipedia.org/wiki/Gelatinous_cube) - [Wikipedia — Greyhawk (supplement)](https://en.wikipedia.org/wiki/Greyhawk_(supplement)) - [Wikipedia — List of D&D monsters (1974–76)](https://en.wikipedia.org/wiki/List_of_Dungeons_%26_Dragons_monsters_(1974%E2%80%9376)) --- From The Lantern Hall (https://www.lanternhall.org/), a museum of fantasy literature and roleplaying games.