Gargantuan monstrosity, unaligned

Armor Class: 16

Hit Points: 395

Speed: 0 ft

STR

16 +3

DEX

12 +1

CON

18 +4

INT

11 +0

WIS

11 +0

CHA

9 -1

Saving Throws: Str +8, Con +9

Damage Vulnerabilities: Radiant

Damage Immunities: Acid, Necrotic, Poison, Psychic

Condition Immunities: Blinded, Charmed, Deafened, Exhaustion, Frightened, Paralyzed, Petrified, Poisoned, Prone, Restrained

Senses: darkvision 120 ft., passive Perception 12

Actions

Multiattack. The Mother makes three attacks.   Tentacle Sweep. The Mother commands a tentacle to sweep the surrounding area. The commanded tentacle attacks all adjacent spaces requiring anyone adjacent to make a DC 14 Dexterity (Acrobatics) saving throw or suffer 2d10+3 bludgeoning damage and be knocked prone. A success results in the affected target taking only half damage and not being knocked prone. A target that is already prone automatically fails this save.    Vile Venom. Ranged Weapon Attack: +6 to hit, reach 60 ft., one target. Hit: 2d10+1 acid damage.   Puncture. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 2d10+3 piercing damage.   Acid Rain. Ranged Weapon Attack: 15x15 ft. area. DC 15 Constitution saving throw, 3d10 poison damage vs all targets. Successful save results in half damage.

Legendary Actions

The Mother can take 3 legendary actions, using the options listed below. It can only take one legendary action at a time and only at the end of another creature's turn. The Mother regains spent legendary actions at the start of its turn.   Spawn Tentacle. The Mother spawns a tentacle anywhere within her lair. Tentacles have an AC of 15, 15 hit points each, and 0 movement speed.   Tentacle Sweep. The Mother commands a tentacle to sweep the surrounding area. The commanded tentacle attacks all adjacent spaces requiring anyone adjacent to make a DC 14 Dexterity (Acrobatics) saving throw or suffer 2d10+3 bludgeoning damage and be knocked prone. A success results in the affected target taking only half damage and not being knocked prone. A target that is already prone automatically fails this save.    Spew Spawn. The Mother spews forth 1d6+1 voidlings which spawn at her location. These voidlings have an AC of 10, 5 hit points each, 25 movement speed, and take their turns immediately. On death, voidlings explode, dealing 1d6 acid damage to all adjacent targets with no save.   Vile Venom. The Mother spits a stream of viscous and deadly acid at a target within 60 ft. This attack is made at +6 to hit and deals 1d10+1 acid damage to the target.   Puncture. The Mother attempts to skewer a target within 10 ft. of her with her bladed spider-like appendages. This attack is made at +8 to hit and deals 1d10+3 piercing damage to the target.   Devour. The Mother drains 1d10+4 health from her imprisoned target with no save, or consumes an adjacent voidling to heal for 1d10+4 health.

Lair Actions

When fighting inside its lair, the Mother can invoke additional effects to take lair actions. On initiative count 20 (losing ties), the Mother can take one lair action to cause one of the following effects:

• The Swarm. When the Mother uses Spew Spawn it spawns an additional 1d4+1 voidlings until initiative count 20 on the next round.

• Carnage. When the Mother uses carnage as her lair action, voidlings explode for twice as much damage (2d6) when they die until initiative count 20 on the next round.

• Violent Delights. When the Mother uses violent delights as her lair action, Devour becomes enhanced, draining 2d10+4 health from her imprisoned target or healing her for 2d10+4 health when she consumes an adjacent voidling until initiative count 20 on the next round.

The lair of the Mother is filled with grotesque boils, and the walls and ground are coated in a thick viscous bloody slime. Strands of goo and sinew coat the ceiling, and a disturbing gurgling sound can be heard from deep within the chasm. Small creatures that glow faintly with an otherworldly purple energy skitter across the floor underfoot. Stepping on one, it emits a violent pop and squish; as its innards explode across the ground; the glowing fades.