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

Unusual Nature. The zombie doesn’t require air, food, drink, or sleep.

Multiattack.  The zombie makes two Greataxe attacks. One of the attacks can be replaced by a Choke attack. It also uses Stomp.

Choke. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 14 (3d6 + 4) bludgeoning damage. The target is grappled (escape DC 15) if it is a Large or smaller creature and the zombie doesn't have any other creatures grappled. Until this grapple ends, the target takes 7 (2d6) bludgeoning damage at the start of each of its turns.

Greataxe. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 23 (3d12 + 4) slashing damage.

Stomp. The zombie stomps, creating a mighty shockwave. Each creature on the ground within 5 feet of the zombie must succeed on a DC 15 Strength or Dexterity saving throw (target's choice) or be knocked prone and take 9 (2d8) bludgeoning damage. On a successful save, the creature takes only half the damage and isn't knocked prone.