Hi all, this is my first attempt homebrewing an AO monster, though I've used some of the principles in AO before. I'm brewing this as a solo boss for a party of 6-7 level 7 PCs. One of my main worries is avoiding quick boss death by way of a paladin / fighter / rogue mega-damage round. They will probably go into the fight without all their resources. The fight will be in a room with some dynamic terrain (for hiding), but the room will be small enough that, after five rounds the whole room will be filled ooze.

Zotzilaha the Undying, servant of Zuggtmoy

A crawling mass of black and red mold, covered in star-filled eyes.

Str 20 ( 5) Int 16 ( 3)
Dex 11 ( 1) Wis 14 ( 2)
Con 18 ( 4) Cha 18 ( 4)

AC  18  HP  550

Damage Immunities: Non-magical bludgeoning, piercing, and slashing. Condition immunities: Blinded, Deafened, Charmed, Grappled, Poisoned Senses: Darkvision 120ft, Blindsight 120ft Languages: Common, Abyssal, Telepathy 120ft

ACTIONS

Multiattack: Zotzilaha makes three pseudopod attacks, or it may give up one pseudopod attack to Constrict or Engulf an already grappled target.

Psuedopod: Melee Weapon Attack: 9 to hit, reach 10 ft., one target. Hit: 18 (4d6 4) bludgeoning damage. On any successful attack, the pseudopod can choose to grapple the target (escape DC 18).

Constrict: Zotzilaha constricts a Medium or smaller creature grappled by it. The constricted restrained and it must succeed on a DC 14 Constitution saving throw at the start of each of Zotzilaha's turns or take 13 (2d8 4) bludgeoning damage.

Engulf: Zotzilaha engulfs a Medium or smaller creature grappled by it. The engulfed target is blinded, restrained, and unable to breathe, and it must succeed on a DC 14 Constitution saving throw at the start of each of Zotzilaha's turns or take 13 (2d8 4) necrotic damage. If the mound moves, the engulfed target moves with it.

REACTIONS

Sharing is Caring. (Adapted from the AO Aboleth!) Immediately after taking damage, Zotzilaha can use its reaction to force a creature currently grappled to make a DC 16 Wisdom saving throw. On a failed save, the target takes the damage instead of Zotzilaha as an equal amount of necrotic damage. On a successful save, the target takes half the damage as necrotic damage and Zotzilaha takes the other half.

My Wound is My Body. Immediately after taking slashing damage, Zotzilaha can use its reaction to make a Constitution saving throw, DC the damage taken. On a successful save, he takes no damage and, instead, releases a Spore Child (see below).

VILLAIN ACTIONS

Fungal Nucleus (each round): Zotzilaha's central fungal body oozes a spore-filled fluid. Every round it oozes 5ft in each direction. The ooze is difficult terrain. Any creature who ends its turn in the ooze must make a CON save (DC 15); on a failed save they take d8 2 poison damage.

Call the Children (Round 2) - Zotzilaha calls the spirits of his faithful and grants them new life in fungal bodies as Spore Children (see below) which rise from his spreading, spore-filled ooze. 1d4 2 faithful spirits rise from the floor within Zotzilaha's ooze and are given fungal bodies to possess. (They act as a squad on their own initiative.)

Forced Communion (Round 3) - Zotzilaha attempts to compel any grappled creatures into communion with its patron, Zuggtmoy. The target must make a WIS save (DC 15). On a failed save, the target is Stunned for 1d4 rounds or until they are no longer in physical contact with Zotzilaha.

Spore Children

Str 20 ( 5) Int 5 (-3)
Dex 14 ( 2) Wis 14 ( 2)
Con 18 ( 4) Cha 9 (-1)

AC  16  HP  90

ACTIONS

Multiattack: The Children makes two slam attacks.

Slam: Melee Weapon Attack: 5 to hit, one target. Hit: 18 (2d6 4) bludgeoning damage.

REACTIONS

Spore-cloud Death: When reduced to 0 HP, the Child may use their reaction to explode into a spore cloud. Any creature within 10ft makes a DEX save (DC 15); on a failed save the creature takes 2d6 2 poison damage on a successful save the creature takes half as much.