Gargantuan ooze, chaotic neutral

Armor Class 5

Hit Points 217 (14d20+70)

Speed 10 ft.

STR DEX CON INT WIS CHA
18 (+4) 1 (-5) 20 (+5) 12 (+1) 10 (0) 3 (-4)

Damage Resistances acid, cold, fire

Damage Immunities poison

Condition Immunities blinded, charmed, deafened, exhaustion, frightened, poisoned, prone

Senses blindsight 60 ft. (blind beyond this radius)

Languages telepathy 50 ft.

Challenge 10 (5,900 XP)

Source. tales from the yawning portal, page 248

Ooze Nature. White Maw doesn’t require sleep.

Amorphous Form. White Maw can occupy another creature’s space and vice versa.

Corrode Metal. Any nonmagical weapon made of metal that hits White Maw 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 White Maw is destroyed after dealing damage.

White Maw can eat through 2-inch-thick, nonmagical metal in 1 round.

False Appearance. While White Maw remains motionless, it is indistinguishable from white stone.

Killer Response. Any creature that starts its turn in White Maw’s space is targeted by a pseudopod attack if White Maw isn’t incapacitated.

Actions

Pseudopod. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 22 (4d8 + 4) bludgeoning damage plus 9 (2d8) acid damage. 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.