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.

Sturdier Than Average. Due to the honey comb packed inside it's body cavities, this zombie is slightly more sturdy than the average variety. It gets a +2 to it's Constitution.

Persistent Defenders. A stalwart group of wasps stay within the zombie's space to protect their hive, even if the swarm of wasps has died/been killed, or regardless of the space between the swarm and the zombie. Any creature that starts it's turn within 5 feet of the zombie, or ends it's turn within 5 feet, must make a DC 12 Dexterity saving throw, taking (1d4) piercing damage on a failed save. They then make a DC 10 Constitution saving throw, taking (1d4) poison damage on a failed save, or half as much on a successful one. A successful Dexterity save negates all damage from this ability for the this round.

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

Shambling Hive. The first time the zombie is damaged, struck, or jostled in any way, a Swarm Of Wasps spills out of the various openings in the zombie's body. The swarm uses the same statistics as the Swarm Of Insects found in the Basic Rules, except that they also have a flight speed of 15 ft., and the Bite action is replaced with Sting. Melee Weapon Attack: +3 to hit, reach 0 ft., one target in the swarm's space. Hit: 10 (4d4) piercing damage, or 5 (2d4) piercing damage if the swarm has half of its hit points or fewer. The target must make a DC 10 Constitution saving throw, taking (2d6) poison damage on a failed save, or half as much damage on a successful one.