Your Intelligence score increases by 2, and your Wisdom or Charisma score increases by 1.

Mind flayers live about 125 years. They are warm-blooded amphibians, and spend the first 10 years of life as tadpoles, swimming in the elder-brain pool until they either die (which most do) or grow into adult illithids after being implanted in a humanoid host.

Illithids are lawful evil, serving their own schemes and the far reaching plots of the Elder Brain. As an outcast, you may still harbor your own selfish schemes. Most outcasts tend towards chaotic neutral or true neutrality.

A mind flayer stands around the same height as a human, typically between 5'4" and 6'2", having humanoid shape and narrow build.

Your base walking speed is 30 feet.

Your darkvision has a range of 120 feet.

Your true aberrant nature is entirely different from those of other mortal races. While you understand the emotions of other humanoids, you have trouble picking up on social cues and understanding intent. You have disadvantage on all Charisma ability checks which you aren’t proficient in.

Cut off from the knowledge and experience of your hivemind, you have had to acquire your own. You are proficient in one of the following skills: Arcana, History, Religion, or Nature.

Mind Flayers view those of their race who dabble in the arcane to be deviants of the worst kind, and as such will shun them if their practices are ever discovered. You know one cantrip from the Wizard or Sorcerer spell list.

When you reach 3rd level, you can cast the levitate spell on yourself once with this trait and regain the ability to do so when you finish a long rest. When you reach 5th level, you can cast the detect thoughts spell once with this trait and regain the ability to do so on a long rest. Intelligence is your spellcasting ability for these spells, and you cast them without requiring components.

When you reduce a living creature within 5 feet of you to 0 hit points using a special melee attack (with a bonus to hit equal to your proficiency bonus plus your INT modifier), you can devour their brain as a reaction, gaining temporary hit points equal to your level + your proficiency bonus. In addition, you may receive the answer to one question that the consumed brain knew the answer to (at the DM’s discretion). This creature must have a size of Medium or smaller. Alternatively, you may use an action to consume the brain of a creature that has died within the last minute and gain the same benefits. When you devour a brain, you are considered fed for 1d10+5 days. You regain use of this trait once you complete a long rest.

You can use an action to psionically emit a psychic blast in a 15-foot cone. When you use your mind blast, each creature in the area of the blast must make an Intelligence saving throw. The DC for this saving throw equals 8 + your Intelligence modifier + your proficiency bonus. A creature takes 2d6 psychic damage on a failed save, and half as much damage on a successful one. The damage increases to 3d6 at 6th level, 4d6 at 11th level, and 5d6 at 16th level. After you use your mind blast, you can’t use it again until you complete a short or long rest.

You can speak, read, and write Undercommon or Common, and Deep Speech.

You have telepathy out to a range of 60 feet. You can communicate with one creature at a time using this trait, who can respond in the same manner. Alternatively, you can communicate with any number of creatures of your choice out to a range of 15 feet. These creatures can not respond in the same manner. You don’t need to share a language with a creature to communicate with it using this trait. You must be conscious to use this trait.