Bloated Eldritch Husk

Pack Tactics. The husk has advantage on an attack roll against a creature if at least one of the husk’s allies is within 5 feet of the creature and the ally isn’t incapacitated.

Undead Fortitude. If damage reduces the husk to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is psychic or from a critical hit. On a success, the husk drops to 1 hit point instead.

Burst. If the husk is reduced to 0 hit points and doesn't gain the benefit of undead fortitude or by a critical hit the husk explodes. Each creature within 5 feet of it must make a DC 14 Constitution saving throw, taking 14 (4d6) necrotic damage on a failed save, or half as much damage on a successful one. Creatures who fail this saving throw by 5 or more gain one level of contamination.

Multiattack. The husk makes two claw attacks. For each of these attacks that reduces a creature to 0 hit points, the husk can make an additional claw attack.

Claw. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) slashing damage.

Bile Spray (Recharge 5–6). The husk exhales a 15-foot cone of acid. Each creature in that area must succeed on a DC 14 Dexterity saving throw, taking 13(3d8) acid damage on a failed save, or half as much damage on a successful one. Creatures who fail their saving throw by 5 or more gain one level of contamination.