Chimental

Multiattack. The chimental makes three attacks: one with its claws, one with its tentacles, and one other attack.

Horns. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 11 (1d12 + 4) bludgeoning damage.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) piercing damage.

Beak. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 12 (3d4 + 4) piercing damage.

Claws. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 8 (1d6 + 4) slashing damage.

Tentacles. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 12 (2d8 + 3) psychic damage. Any creature hit with this attack must succeed a DC 10 Dexterity saving throw or be grappled (escape DC 12).

Brine Breath (Recharge 5–6). One of the three heads exhales brine in a 60-foot line that is 10 feet wide. Each creature in that area must make a DC 15 Intelligence saving throw, taking 28 (5d10) psychic damage on a failed save, or half as much damage on a successful one. On a success or failure, if the creature has an Intelligence score of 4 or more, it becomes infested with illithid tadpoles.

While infested, the creature takes 7 (1d12) psychic damage at the start of each of its turns. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself after it succeeds on three of these saves. If the creature is targeted by magic that ends a curse or restores 20 hit points or more, the tadpoles infesting the creature are killed instantly, ending the effect on the creature. If a creature is reduced to 0 hit points while infested, the creature is stable but remains unconscious for 6d12 hours. When the period of unconsciousness ends, the creature transforms into a mind flayer (see the Monster Manual) with all its hit points.

Helpless Prey. When a creature is grappled by the Chimental's tentacles and none of the three heads have taken or dealt damage this turn, the Chimental may attack that creature with its horns, its bite, and its beak before tossing the creature away.