Gargantuan Ooze, unaligned
Armor Class 16 (natural armor)
Hit Points 170 (11d20+55)
Speed fly +40, walk +5
Challenge 10
Skills perception +1
Damage Resistances cold
Damage Immunities acid
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, prone
Senses blindsight 120' (blind beyond), passive Perception 15
Languages —
Acidic Fog. A creature that starts its turn in the wandering haze's space takes 7 (2d6) acid.
Cloud Form. Can move through a space as narrow as 1 inch wide with o squeezing and can enter a hostile creature's space and vice versa. The haze's space is heavily obscured.
False Appearance. While motionless indistinguishable from ordinary cloud or fog bank.
Ooze Nature. Doesn't require sleep.
Multiattack. Three Pseudopod attacks.
Pseudopod. Melee Weapon Attack: +10 to hit, 10 ft., one target, 11 (2d4+6) bludgeoning damage + 7 (2d6) acid.
Sheath of Chaos. Wraps its cloudy form tighter around those within it. Each creature in the wandering haze's space: 27 (6d8) psychic and is disoriented until end of its next turn as its mind fills with gibbering terrors of chaos that created haze's form (DC 17 Wis half damage and not disoriented). When a disoriented creature moves it moves in a random direction.
Acidic Cloudburst (Recharge 5-6). Releases a deluge of acid. Each creature within 10 ft. of it: 35 (10d6) acid and speed halved 1 min (DC 17 Dex half damage and speed not reduced). A creature with halved speed can make a DC 17 Con save at the end of each of its turns success ends effect on itself.
Source: Tome of Beasts 3 · OGL/Open