Slam (Material Form Only)

Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) bludgeoning damage and the target must make a successful DC 13 Constitution saving throw or become diseased. The disease has little effect for 1 minute; during that time, it can be removed by bless, lesser restoration, or comparable magic. After 1 minute, the diseased creature's skin becomes translucent and slimy. The creature cannot regain hit points unless it is at least partially underwater, and the disease can only be removed by heal or comparable magic. Unless the creature is either fully submerged or frequently doused with water, it takes 6 (1d12) acid damage every 10 minutes. If a creature dies while diseased, it rises in 2d6 rounds as a nihilethic zombie. This zombie is permanently dominated by the nihileth that commands the attacking zombie.

Withering Touch (Ethereal Form)

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

Form Swap

As a bonus action, the nihilethic zombie can alter between its material and ethereal forms at will.

Sacrifice Life

A nihilethic zombie can sacrifice itself to heal a nihileth within 30 feet of it. All of its remaining hit points transfer to the nihileth in the form of healing. The nihilethic zombie is reduced to 0 hit points and it doesn't make an Undead Fortitude saving throw. A nihileth cannot be healed above its maximum hit points in this manner.