Ethereal Body. A thought eater’s skin and organs are composed primarily of ethereal tissue, making it difficult to hit. For every minute the thought eater remains on a plane other than the Ethereal Plane, it must deal at least 1 point of psychic damage or take 1d6 points of psychic damage as its body begins to dissipate.

Ethereal Passage. A thought eater can move between the Ethereal Plane and the Material Plane as a move action without provoking opportunity attacks. This movement causes the thought eater 1 point of psychic damage.

Improved Initiative. The thought eater gets a +4 bonus on initiative checks, in addition to its Dexterity modifier.

Multiattack. The thought eater makes two Bite attacks.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d4 + 4) piercing damage. On a hit with its bite attack, the thought eather also uses eat thoughts.

Eat Thoughts. A creature that takes damage from a thought eater’s bite loses some of its thoughts, as the thought eater drains them to nourish itself.
  If the target is a spellcaster, they lose a single spell slot of 1st level or higher. A spellcaster chooses the spell slot they lose from this ability.
 If the target isn't a spellcaster or has no remaining spell slots of 1st-level or higher, they must succeed on a DC 15 Intelligence saving throw or take 14 (4d6) psychic damage and become stunned until the end of the thought eater's next turn. On a successful save, the creature takes half as much damage and isn’t stunned.
  When a creature loses a spell slot or takes psychic damage from this attack, the thought eater gains 14 (4d6) hit points, with any in excess of 32 applied as temporary HP.

Innate Spellcasting (Psionics). The thought eater casts one of the following spells, requiring no spell components and using Intelligence as its spellcasting ability (spell save DC 15):

At will: Dancing Lights, Mage Hand, Mind Sliver

2/day each: Detect Thoughts, Dissonant Whispers, Protection from Energy

1/day: Identify