Medium Aberration, Chaotic Neutral
Armor Class 9 Initiative −1 (9) Hit Points 52 (7d8 + 21) Speed 20 ft., Swim 20 ft.
Saving Throws Str +0, Dex −1, Con +3, Int −4, Wis +0, Cha −2
Damage Immunities Prone
Senses Darkvision 60 ft.; Passive Perception 10
Languages None
Challenge Rating 2
The ground in a 10-foot Emanation originating from the mouther is Difficult Terrain.
The mouther babbles incoherently while it doesn't have the Incapacitated condition. Wisdom Saving Throw: DC 10, any creature that starts its turn within 20 feet of the mouther while it is babbling. Failure: The target rolls 1d8 to determine what it does during the current turn:
1–4. The target does nothing.
5–6. The target takes no action or Bonus Action and uses all its movement to move in a random direction.
7–8. The target makes a melee attack against a randomly determined creature within its reach or does nothing if it can't make such an attack.
Melee Attack Roll: +2, reach 5 ft. Hit: 7 (2d6) Piercing damage. If the target is a Medium or smaller creature, it has the Prone condition. The target dies if it is reduced to 0 Hit Points by this attack. Its body is then absorbed into the mouther, leaving only equipment behind.
Dexterity Saving Throw: DC 10, each creature in a 10-foot-radius Sphere centered on a point within 30 feet. Failure: 7 (2d6) Radiant damage, and the target has the Blinded condition until the end of the mouther's next turn.