Crystal ooze

A crystal ooze was an offshoot of a gray ooze, and had adapted to living in water.

Description
These cousins to the gray oozes, when in water, were very hard to spot. Their translucent bodies were as clear as glass, but sometimes featured swirls of white. In order to conceal themselves even more, they usually chose dark, murky pools of water, instead of clear water.

Unlike other oozes, they were proficient at swimming and wading through liquids. These rare oozes had animal level intelligence.

Combat
Crystal oozes were generally more difficult to fight that 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 themself paralyzed and quickly consumed.

Such oozes had a variety of immunities. They could not be harmed by acid, fire, heat, or cold-based attacks. Only magical and electrical energy seemed to harm the beings, except for raw damage from metal weapons.

Ecology
Despite being used to existing in water, they were also able to survive outside it for many hours, where they could hunt for prey. The oozes also scavenged almost anything for food, but nothing made of metal. Thus, lairs of crystal oozes may have contained metal weapons and pieces of armor.

As with gray oozes, they reproduced by budding (crystal) pods, which took up to 10 days to hatch into newly formed gray oozes. If food was scarce, the oozes ate their offspring, but otherwise did not, and may have lived aside them.

They were known to dwell in various places throughout Undermountain

Appearances

 * Magazines
 * Dungeon magazine 30: "... And a Dozen Eggs"