Mordenkainen's Tome of Foes
Life Hunger. If a creature the Hungry can see regains hit points, the Hungry gains two benefits until the end of its next turn: it has advantage on attack rolls, and its bite deals an extra 7 (1d12) necrotic damage on a hit.
Multiattack. The Hungry makes two attacks: one with its bite, and one with its claws. Bite. Melee Weapon Attack: +6 to hit, reach 5ft., one target. Hit: 7 (1d6+4) piercing damage plus 8 (2d8) necrotic damage. Claws. Melee Weapon Attack: +6 to hit, reach 10ft., one target. Hit: 10 (2d6+4) slashing damage. If the target is Medium or smaller, it is grappled (escape DC 14) and restrained until the grapple ends. While grappling a creature, the Hungry can't attack with its claws.