While making the demon sketches (there are more that I feel are too bad to even share) I also created this, and wanted to make it into a monster proper.

Here is my blurb on it.


Octem Devourer.
Abberation, large. Chaotic Evil

AC 16 (natural) HP Avrg 92
Speed 20. Aquatic speed 50

STR 22 (+6) DEX 10 (+0) CON 26 (+8) INT 14 (+2) WIS 6 (-3) CHA 4 (-4)

Skills: Perception (passive +16, magical)
Senses: Blind sight 60ft - Darkvision 120ft.

Languages: Common. Abyssal.

Challenge rating: ?? need play test

Resistances: Fire, Bludgning, Psychic.

Immunities: Cold.


Vulnerabilities: Lightning

Abillities:

Aquatic Warp: As a bonus action, the Octem Devourer can teleport through any water pool to another. (240ft)
Recharges on a 6, rolled at the start of every turn.

Detatched Head Bomb: When slain, the Octem devourer regains half its total hitpoints and looses a head.
The head will attempt to attack nearby foes. The Octem head will takes its turn in the turn order, right after the Octem Devourer.

Octem devourers typically have 1 head for every five years it's been alive. Max of 4. (then it spawns a new Octem as a new creature)


Multi attack - The Octem devourer takes 4 attacks. 1 bite (+8 to hit, 2d6+6 Piercing) 1 Spit attack (+8 to hit, 1d12 Acid DMG, 120ft range)
2 Tentacle slaps (+8 1d6+6 bludgning, 15ft range)

Grapple: In leu of attacking with any tentacle slap, it can attempt to grapple a foe. A foe grappled will take CRITICAL hits from BITE
attacks




SEVERED HEAD:

Abberation.

AC 11
HP 16
Movement: 20ft (flying) 40ft (swim speed)
Resistace: All damage.

Dies after 12 seconds. (2 rounds)

Attacks with 1 attacks -
Bite (+8) (2d6+6)
OR
Explode
all creatures in 20ft, must succede a WIS saving throw (16) or take 6d8+6 Psychic damage and be knocked prone.
Saves take half damage and is not knocked prone.
lore:
Octem devourers live in deep lakes and rivers that are either brackish or freshwater - Cannot survive in saltwater.
Typically a very lone hunter, Octems can lay dorment for years on end, if well fed, and only attacks when hunting.

While the Octem can speak, it will often not do so its entire life. Octems typically live for fifty years then dies of natural causes.

Every five years, the Octem replaces its front most head, shifting the current head back into a hump - the creature undergoes a
chryssalis, typically in a cave, while the new head grows in over a few weeks.
The new head will display a new form of random "personallity", such as aggressive, paranoid, tyrannical, peaceful, gluttonous or even chivalrous.