As with gray oozes, they reproduced by budding (crystal) pods, which took up to ten days to hatch into newly formed gray oozes. If food was scarce, the oozes ate their offspring, but otherwise did not, and might live alongside them.
These oozes had a variety of immunities. Such as being impervious to harm by acid, fire, heat, or cold. Only magical and electrical energy seemed to harm the beings, except for raw damage from metal weapons.
Crystal oozes were generally more difficult to fight than other oozes. Although they could not corrode metal, they directly poisoned cloth, flesh, and wood. They struck out at their opponents, much like snakes, and then tried to submerge or smother their foes. If the oozes directly touched any part of a typical living being, the being would find itself paralyzed and quickly consumed.
Many were known to dwell in various places throughout Undermountain. In the Hordelands, they could occasionally be found in the lakes, rivers, and swamps of the Ama Basin during the summer season.
- Doug Stewart (June 1993). Monstrous Manual. (TSR, Inc), pp. 278–279. ISBN 1-5607-6619-0.
- David "Zeb" Cook, et al. (1989). Monstrous Compendium Volume Two. (TSR, Inc). ISBN 0-8803-8753-X.
- Gary Gygax (August 1983). Monster Manual II 1st edition. (TSR, Inc), p. 27. ISBN 0-88038-031-4.
- Jean Rabe, Norm Ritchie (Feburary 1994). The Ruins of Undermountain II: The Deep Levels (Campaign Guide). (TSR, Inc). ISBN 1-5607-6821-5.
- David Cook (August 1990). “Volume II”. In Steve Winter ed. The Horde (TSR, Inc.), p. 122. ISBN 0-88038-868-4.