Regeneration. Zuggtmoy's Revenant regains 10 hit points at the start of its turn. If the revenant takes fire damage, this trait doesn’t function at the start of the revenant’s next turn. 

Lingering Spores. When the revenant is killed, its body lingers. After 24 hours, the body becomes an inanimate fungus. Walking within 15 feet of the fungus activates its control spores ability. Burning the body after killing it removes this effect. 

Zuggtmoy's Purpose. The revenant is delivered a task and will remove anything in its way by force. It responds to violence with violence. It ignores everything else. 

False Fortitude. If damage reduces the revenant to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is fire or from a critical hit. On a success, the revenant loses a limb but drops to 1 hit point instead. A lost limb reduces its AC by 2.

Multiattack. The revenant uses Control Spores and then makes two pulverising fist attacks.

Pulverising Fist. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage. If the target is a medium or smaller creature, the target takes an extra 14 (4d6) bludgeoning damage.

Rapport Spores (3/Day). A 10-foot radius of spores extends from the revenant. These spores can go around corners and affect only creatures with an Intelligence of 2 or higher that aren’t undead, constructs, or elementals. Affected creatures can communicate telepathically with one another while they are within 30 feet of each other. A Zuggtmoy's Revenant affected by Rapport Spores can communicate and listen to creatures under the effect of Rapport Spores up to a range of 120 feet. The effect lasts for 1 hour.

Control Spores. The revenant targets one medium or smaller creature it can see within 30 feet of it. The target must make a DC 12 Constitution saving throw. On a failure, the target is poisoned indefinitely. Any effect that removes poison removes the condition as normal, but the following still applies. The creature is now affected by Zuggtmoys control spores. At the end of every long rest, the creature must make a DC10 sanity saving throw. Each failure slowly changes the creature's body and gives it access to new abilities. Failing once allows the creature to be able to communicate to anyone under the effect of Rapport Spores up to 120 feet. Upon failing 3 times the creature gains the senses of a Zuggtmoy's Revenant. Upon failing 5 times the creature becomes a Zuggtmoy's Revenant. The control spores may be negated with Remove Curse, Dispel Evil or Greater Restoration.