Gibbering Mouther

The ground within 10 feet of the mouther is dough-like difficult terrain. A creature that starts its turn in the area must succeed on a DC 13 STR save or its speed is halved until the start of its next turn.

The mouther is resistant to the charmed, frightened, paralyzed, and stunned conditions, and it has advantage on saves against spells or effects that would alter its form.

The mouther babbles incoherently while it can see any creature and isn't incapacitated. A creature that starts its turn within 20 feet of the mouther and that can hear the gibbering must succeed on a DC 13 WIS save or it can't take reactions until the start of its next turn and must roll a d8 to determine what it does during its turn. On a 1 to 4, the creature does nothing. On a 5 or 6, the creature takes no action or bonus action and moves its full speed in a randomly determined direction. On a 7 or 8, the creature makes a melee attack against a randomly determined creature within its reach or does nothing if it can't make such an attack.

Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 11 (2d8+2) piercing damage.

The gibbering mouther makes two Bite attacks. If both attacks hit one Medium or smaller creature, the target must succeed on a DC 13 STR save or be knocked prone.

One creature the mouther can see within 30 feet of it must succeed on a DC 13 WIS save or take 18 (4d8) psychic damage and suffer a random, short-term dread effect for 1 minute

The mouther spits an otherworldly goo at up to two creatures it can see within 30 feet of it. Each target must succeed on a DC 13 DEX save or be blinded until the end of its next turn.