Tentacle Devil

An old one hybrid. Created from willing volunteers through ritual in the Necronomicon. While it is called a devil it only in name and has nothing to do with devils and it is not from the nine hells. This is truly a hybrid of madness from the old ones.

XP: 2,300
Type: Medium old one hybrid, Neutral evil
Hit Dice: d8 HP: 56 (9d8 + 9)
Initiative: +1
Speed: Speed 25 ft., swim 60 ft.
Armor Class: 14 (natural armor) Touch AC: 14 Flat Foot AC: 14
Base Attack:
Attacks: Multiattack. The hybrid makes three melee attacks: two with its tentacles and one with its bite. It can use cause madness in place of any melee attack. Tentacles. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) piercing damage plus 7 (2d6) poison damage.

Special Qualities: 
Damage Resistances cold; bludgeoning, piercing, and slashing from nonmagical attacks that aren't silvered.
Damage Immunities fire, poison
Condition Immunities poisoned.
Amphibious. The hybrid can breathe air and water. 
Star Sight. Magical darkness doesn't impede the hybrids darkvision.
Magic Resistance. CR 14
Special Attacks: Cause madness. Ranged Spell Attack: +4 to hit, range 150 ft., one target. Hit: 14 (4d6) psychic damage.
Saves: Fort. ++7 Ref. +4 Will. +7
Abilities: STR 18 (+4) DEX 13 (+1) Con 12 (+1) INT 13 (+1) WIS 18 (+4) 12 Cha (+1)
Skills: Senses darkvision 120 ft., passive Perception 14
Feats:
Environments: water, any, land any
Organizations: none
Challenge Rating: 6
Treasure: N/A
Alignment: Neutral Evil 
Advancement: as class