Large Aberration, Chaotic Evil

Armor Class: 14 (17 Mage Armor)

Hit Points: 102 (14d10+42)

Speed: 30 ft., fly 40 ft. (hover)

STR 14/+2

DEX 18/+4

CON 16/+3

INT 18/+4

WIS 14/+2

CHA 14/+2

Saving Throws: Dexterity +7, Wisdom +5

Skills: Stealth +7, Perception +5

Senses: Blindsight 60 ft., Passive Perception 15

Condition Immunities: Prone

Languages: Deep Speech, Undercommon, Telepathy 120 ft.

Challenge: 8

Proficiency Bonus: +3

Mind and Matter. Putamen Overmind can innately cast the Phantasmal Force, Catapult (2nd level), Mage Armor spells (DC 15, Spellcasting Ability – Intelligence) at will without requiring any components. 

Psionic Anchor. As a bonus action, Overmind can place a Psionic Anchor at a point of its choosing within 60 feet of it. All creatures  that are within 30 feet of the anchor, or start their turn in the area, must make a DC 15 Strength Saving throw, being forced to move up to 20 feet towards the anchor on a failure.
All creatures in the area of the anchor gain flying speed equal to their swimming speed for as long as they are in the area, and the area is considered difficult terrain if they try to move away from the anchor. 

• The Overmind can voluntarily choose to succeed or fail on the Strength saving throw when in the area of a Psionic Anchor, and it ignores difficult terrain created by it. 

Any creatures that go prone in the area don’t fall to the ground, but are instead moved up to 20 feet towards the anchor.
If a creature goes through another creature’s space due to being dragged by the anchor, the other creature must make a DC 15 Dexterity saving throw, stopping the dragged creature’s movement and making them both take 4d6 bludgeoning damage on a failure. 

A single Putamen Overmind can only have two active Psionic Anchors at once, and it can dismiss any of its Anchors as a bonus action. If the areas of two or more Psionic Anchors intersect, their combined area works as if they were created by a single Anchor that is found in the center of their combined areas. 

Neural Nexus. Once it reaches full maturity, a Putamen Overmind’s tendrils lose their ability to drain the mental powers of its victims through direct contact. Instead they serve as amplifiers and conduits of its psionic power and of its ability to assault the mind. As a bonus action on each of its turns, the Overmind can cause one of the following effects. 

• Kinetic Push. All creatures within 15 feet of the Overmind must make a DC 15 Strength saving throw, being pushed 30 feet away from the Overmind on a failure, taking 4d6 bludgeoning damage and having  their forced movement stopped if they hit a solid object
• Mind Diffraction Field. Putamen Overmind becomes invisible to all creatures that are 15 feet or further away from it and to creatures with less than half of their maximum Hit Points until the start of its next turn.   
• Hate Circuit. All creatures in a 10-foot radius sphere within 45 feet of the Overmind must make a DC 15 Intelligence saving throw, being forced to make one weapon attack or spell attack using a spell slot of 1st level or lower of the Overmind’s choice against a creature chosen by the Overmind on a failure. If a creature fails on this saving throw, Overmind learns of all of its available spells and attacks. 

Actions. 

• Multiattack. Putamen Overmind makes two attacks with its Tendrils. 
• Tendril. Melee Weapon Attack: +7 to hit, reach 15 ft., one target. Hit: 18 (4d6+4) piercing damage damage and the creature is grappled and restrained (Escape DC 15). Restrained creatures take 11 (2d6+4) psychic damage at the end of each of their turns.
• Mind Burn. A creature within 60 feet of the Overmind must make a DC 15 Intelligence saving throw, taking 25 (6d6+4) Psychic damage and being unable to use either their bonus action or reaction, depending on what they choose, until the start of the Overmind’s next turn on a failure, or half as much damage and not being affected by any additional effects on a success. Creatures grappled by the Overmind automatically fail on this saving throw, and also have their Intelligence score reduced by 2 until they finish a long rest. 
• Limbic Manipulator (Recharge 5-6). All creature within 45 feet of the Putamen Overmind must make a DC 15 Wisdom saving throw, taking 3d10 psychic damage and becoming frightened of the Putamen Overmind until the end of their next turn on a failure, or half as much damage and not becoming frightened on a success.Creatures affected by this ability also start to see the area around them as if it was affected by the Hallucinatory Terrain (DC 15) spell, the specifics of the terrain are determined by the Overmind.