Read more about Gelatinous Cube at: Wikipedia

Official Site: Wizards of the Coast

A gelatinous cube is a fictional monster from the Dungeons & Dragons fantasy role-playing game. It is described as a ten-foot cube of transparent gel ooze, which is able to absorb and digest organic matter.

Oozes are relatively common antagonists in fantasy fiction; in addition to the oozes of Dungeons & Dragons, examples include the monster from the film The Blob, slime in Dragon Quest, and flan in Final Fantasy. These fictional oozes may have been inspired by microscopic organisms such as amoebae, which, like oozes, can consume organic matter by engulfing it (phagocytosis).

The gelatinous cube is an original invention of Gary Gygax, rather than being inspired by outside sources and adapted to the roleplaying setting, as were many mythological monsters such as the minotaur and dryad, all of which appeared in the 1974 Monsters & Treasure book of the original boxed set.

Being a cube that is a perfect ten feet on each side, it is specifically and perfectly "adapted" to its native environment, the standard, by dungeon corridors which were ubiquitous in the earliest Dungeons & Dragons modules.

Gelatinous Cube has not been a contender in any CBUB matches.