Sources
CR
Type
Size
Alignment
Movement

Telepathic Pentacle

Huge Monstrosity, Unaligned

Armor Class 15 (natural armor)
Hit Points 172 (15d12 + 75)
Speed 30 ft., swim 30 ft., climb 30 ft.
STR
20
+5
DEX
12
+1
CON
20
+5
INT
2
-4
WIS
10
+0
CHA
7
-2
Skills Perception +6
Senses darkvision 60 ft., passive Perception 16
Languages
Challenge 8 (3,900 XP)

Traits

Hold Breath. The Telepathic Pentacle can hold its breath for 1 hour.

Multiple Heads. The Telepathic Pentacle has five heads. While it has more than one head, the Telepathic Pentacle has advantage on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious.

Whenever the Telepathic Pentacle takes 25 or more damage in a single turn, one of its heads dies. If all its heads die, the Telepathic Pentacle dies.

At the end of its turn, it grows two heads for each of its heads that died since its last turn, unless it has taken fire damage since its last turn. The Telepathic Pentacle regains 10 hit points for each head regrown in this way.

Reactive Heads. For each head the Telepathic Pentacle has beyond one, it gets an extra reaction that can be used only for opportunity attacks.

Wakeful. While the Telepathic Pentacle sleeps, at least one of its heads is awake.

Actions

Multiattack. The Telepathic Pentacle makes as many bite attacks as it has heads.

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit:10 (1d10 + 5) piercing damage.

Lore

Months before Ythryn's fall, a circle of mages known as the Telepathic Pentacle tried to fuse their minds together to become a conjoined telepathic force. The procedure went terribly wrong, and their bodies and minds melded into a single monstrosity. Iriolarthas imprisoned the thing in this empty well so that its latent telepathic powers could be tapped by the city's elite. A short obituary is engraved around the lip of the well in Draconic: "Herein lie the immortal remains of the Telepathic…