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.

Multiattack. The Zombie Slaver makes a Net attack and a Trident attack or Makes two Melee attacks.

Net. Ranged Weapon Attack:  +4 to hit, range 5/15 ft., one target. Hit: A Large or smaller creature hit by a net is restrained until freed. A net has no effect on creatures that are formless or Huge or larger. A creature ca choose to take its turn to make a DC 10 Strength check, freeing itself on a success. Dealing 5 or more slashing damage to the net (AC 10) also frees the creature without harming it. If you choose to attack the net you can only make one attack that turn.

Trident. Melee or Ranged Weapon Attack: +4 to hit, reach 5 ft. or range 20/60 ft., one target. Hit:  5 (1d6 + 2) piercing damage.

Slam. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) bludgeoning damage.