Vargouille

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) piercing damage plus 10 (3d6) poison damage.

Abyssal Curse. The vargouille targets one incapacitated Humanoid within 5 feet of it. The target must succeed on a DC 12 Charisma saving throw or become cursed. The cursed target loses 1 point of Charisma after each hour, as its head takes on fiendish aspects. The curse doesn't advance while the target is in sunlight or the area of a daylight spell; don't count that time. When the cursed target's Charisma becomes 2, it dies, and its head tears from its body and becomes a new vargouille. Casting remove curse, greater restoration, or a similar spell on the target before the transformation is complete can end the curse. Doing so undoes the changes made to the target by the curse.

Stunning Shriek (Recharge 5–6). The vargouille shrieks. Each Humanoid and Beast within 30 feet of the vargouille and able to hear it must succeed on a DC 12 Wisdom saving throw or be frightened of the vargouille until the end of the vargouille's next turn. While frightened in this way, a target is stunned. If a target's saving throw is successful or the effect ends for it, the target is immune to the Stunning Shriek of all vargouilles for 1 hour.