Otyugh

The otyugh makes one Bite attack and two Tentacle attacks.

Melee Weapon Attack: +6 to hit, reach 5 ft.. Hit: 12 (2d8 + 3) piercing damage, and the target has the Poisoned condition. Whenever the Poisoned target finishes a Long Rest, it is subjected to the following effect.
Constitution Saving Throw: DC 15.
Failure: The target's Hit Point maximum decreases by 5 (1d10) and doesn't return to normal until the Poisoned condition ends on the target.
Success: The Poisoned condition ends.

Melee Weapon Attack: +6 to hit, reach 10 ft.. Hit: 12 (2d8 + 3) piercing damage. If the target is a Medium or smaller creature, it has the Grappled condition (escape DC 13) from one of two tentacles.

Constitution Saving Throw: DC 14, each creature Grappled by the otyugh.
Failure: 16 (3d8 + 3) bludgeoning damage, and the target has the Stunned condition until the start of the otyugh's next turn.
Success: Half damage only.