Multiattack

The grave behemoth makes two slam attacks.

Slam

Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 19 (3d8 + 6) bludgeoning damage.

Gorge

Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 25 (3d12 + 6) piercing damage plus 14 (4d6) necrotic damage.

Hurl Flesh (Recharge 5-6)

The grave behemoth vomits putrid flesh and 5 (2d4) zombies in a 30-foot cone. Each creature in that area must make a DC 16 Dexterity saving throw. On a failure, a target takes 38 (11d6) necrotic damage and is covered in rotting slime for 1 minute. On a success, a target takes half the necrotic damage and isn't covered in slime. A creature, including the target, can take an action to clean off the slime. Zombies under the grave behemoth's control have advantage on attack rolls against creatures covered in a grave behemoth's slime.