Gray Ooze
Medium Ooze, unaligned
100 XP
Special Abilities
Amorphous
The ooze can move through a space as narrow as 1 inch wide without squeezing.
Corrode Metal
Any nonmagical weapon made of metal that hits the ooze corrodes. After dealing damage, the weapon takes a permanent and cumulative -1 penalty to damage rolls. If its penalty drops to -5, the weapon is destroyed. Nonmagical ammunition made of metal that hits the ooze is destroyed after dealing damage.
The ooze can eat through 2-inch-thick, nonmagical metal in 1 round.
False Appearance
While the ooze remains motionless, it is indistinguishable from an oily pool or wet rock.
Actions
Pseudopod
Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) bludgeoning damage plus 7 (2d6) acid damage, and if the target is wearing nonmagical metal armor, its armor is partly corroded and takes a permanent and cumulative -1 penalty to the AC it offers. The armor is destroyed if the penalty reduces its AC to 10.
Quick Reference
Running This Encounter
Gray Oozes are mindless predators that slowly pursue prey with relentless determination. They deal acid damage on contact, so emphasize the danger of melee engagement. Use the ooze's low AC as a lure—it seems easy to hit, but characters will take damage getting close. Consider using terrain to slow the party's retreat and funnel them toward the ooze.
Combat Tactics
The Gray Ooze has no tactics—it simply moves toward the nearest creature each turn and attacks. It cannot be frightened, charmed, or reasoned with. Use its acidic pseudopod attacks repeatedly, and if reduced to half health, consider splitting it into two smaller oozes to extend the encounter.
Environment & Setting
Gray Oozes thrive in damp dungeons, sewers, and underground caverns where moisture is abundant. Place them in narrow corridors or partially flooded chambers where the party cannot easily avoid contact.