Otyugh

The otyugh 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 otyugh can magically transmit simple messages and images to any creature within 120 feet of it that can understand a language. This form of telepathy doesn't allow the receiving creature to telepathically respond.

Each creature that starts its turn within 10 feet of the otyugh must succeed on a DC 15 CON save or be poisoned until the start of its next turn.

Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 12 (2d8+3) piercing damage. If the target is a creature, it must succeed on a DC 15 CON save or become infected with a disease. Until the disease is cured, the target is poisoned. Every 24 hours that elapse, the infected creature must repeat the save, reducing its HP maximum by 5 (1d10) on a failure. The disease is cured on a success. The creature dies if the disease reduces its HP maximum to 0. This reduction to the creature's HP maximum lasts until it finishes a long rest after the disease is cured.

The otyugh makes one Bite attack and two Tentacle attacks. It can replace both Tentacle attacks with a use of Tentacle Slam.

Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 6 (1d6+3) bludgeoning damage plus 9 (2d8) piercing damage. If the target is Medium or smaller, it is grappled (escape DC 13). The otyugh has two tentacles, each of which can grapple one target.

The otyugh slams creatures grappled by it into each other or into a solid surface. Each creature must make a DC 15 STR save. On a failure, a creature takes 14 (4d6) bludgeoning damage and is stunned until the end of its next turn. On a success, a creature takes half the damage and isn't stunned.