The nearly transparent gelatinous cube travels slowly along dungeon corridors and cave floors, absorbing carrion, creatures, and trash. Inorganic material remains trapped and visible inside the cube’s body. A typical gelatinous cube is ten feet on a side and weighs about 15,000 pounds; however, smaller specimens have been reported.

A gelatinous cube attacks by slamming its body into its prey. It is capable of lashing out with a pseudopod, but usually engulfs foes. Any character hit by a gelatinous cube must save vs. Paralyzation or be paralyzed for 2d4 turns.

Any treasure indicated will be visible inside the creature, which must be slain if the treasure is to be recovered.

Gelatinous cubes are dungeon scavengers. They move slowly through corridors and rooms, absorbing carrion, fungi, algae and other nutrients from the surfaces they touch.

Being silent and virtually transparent, gelatinous cubes have a higher-than-usual chance to surprise (1-3 on 1d6).

Gelatinous cubes can only digest organic material, and they will sometimes sweep up inorganic substances (including metal items such as coins, glass or ceramic items such as potion bottles, etc.). These incidental items are sometimes kept in the body of the ‘cube for many days before being ejected. Such items form the creature’s treasure.