Double tap. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 7+ the damage taken, unless the damage is from a critical hit. On a success, the zombie drops to 1 hit point instead. 

Keen hearing. The zombie will move toward any noise regardless of its origin, and has advantage on all perception checks.

Hoard. Multiply all attack rolls by number of zombies.

Slam. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) bludgeoning damage.

Grab. Grabbed creature is grappled and has disadvantage on checks to escape.

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d10 + 1) piercing damage.

Claw. Melee Weapon Attack: +5 to hit, reach 2d6