Brain, Living

Innate Spellcasting. The Living Brain can cast the following spells, requiring no material components:

At will: Detect Thoughts

3/day each: Charm Person, Command, Sleep

2/day each: Hold Person, Suggestion, Tasha's Mind Whip

1/day each: Confusion, Dominate Person, Mass Suggestion, Telepathy

The Living Brain casts these spells as a 15th-level spellcaster, using Intelligence as its spellcasting ability (spell save DC 15).

Empathic Field. The Living Brain emits a low-level empathic field within a 50-foot radius. This field prevents anyone from achieving surprise when attacking the Living Brain within its range. It also allows the Living Brain to estimate the Intelligence, character class, and experience level of anyone entering the field with great precision.

Protective Shell. The Living Brain can invoke a protective shell three times per day. While the shell is active, it is immune to all damage and effects, and nothing can pass through it. This shell combines the effects of Globe of Invulnerability and Wall of Force. The shell lasts for 1 minute.

Regeneration. The Living Brain regenerates 1 hit point per round while immersed in its fluid bath.

Telepathy. The Living Brain can communicate telepathically with any sentient creature within 60 feet of it, transcending language barriers to convey simple concepts.

Psychic Blast. The Living Brain can unleash a bolt of mental energy as an action, targeting a creature it can see within 60 feet of it. The target must make a Wisdom saving throw (DC 15) or take psychic damage based on its Intelligence, as shown in the chart below. On a successful save, the target takes half damage.

Psychic Domination. The Living Brain targets one creature it can see within 60 feet of it. The target must make a Wisdom saving throw (DC 15) or fall under the brain's control. The Living Brain can maintain control over a dominated creature for up to 24 hours. A dominated creature follows the Living Brain's telepathic commands without question. The brain can have up to 3 creatures under its control at a time. If it attempts to dominate a fourth creature, it must release one of its current thralls.

Mind Shield. When the Living Brain is targeted by a spell or effect that requires a Wisdom saving throw, it can use its reaction to impose disadvantage on the saving throw. If the target fails the saving throw, the Living Brain can choose to negate the spell or effect's impact on itself.

The Living Brain can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time, and only at the end of another creature's turn. The Living Brain regains spent legendary actions at the start of its turn.

Psychic Blast (Costs 2 Actions). The Living Brain uses its Psychic Blast.

Psychic Domination (Costs 3 Actions). The Living Brain uses its Psychic Domination.

Detect Thoughts (Costs 1 Action). The Living Brain can cast Detect Thoughts at will, targeting a creature it can see within 60 feet of it.