Gelatinous cube

The gelatinous cube,, is a monster in nethack. Unlike the Dungeons & Dragons creature from which it is derived, it has no means to engulf the player; however it still possesses the means to paralyze the unwary.

Gelatinous cubes are noteworthy in that as they move they will eat organic items they pass over and engulf most other items (exceptions being rocks or a punished player's iron ball and chain) which are then placed into the cube's inventory. They are thus useful for cleaning useless items out of a level, and the bane of stashes.