You can speak, read, and write Undercommon and Deep Speech

Your Intelligence score increases by 2.

Illithids reach adulthood after 50 years, and can live up to 400 years old.

Illithids live in a society that is dedicated to uphold their colony and to serve the elder brain, making them strongly lean towards lawful. It is common for Illithids to hunt down sentient creatures, devouring their brains, and harvesting their knowledge. The more intelligent the prey, the more valuable and rewarding the catch. Because they see must continue seeking sentient lifeforms to kill, they are strictly evil.

Illithid never grow taller than 6 feet and have slender builds. Your size is Medium.

Your base walking speed is 30 feet.

You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can't discern color in darkness, only shades of gray.

Once you reach 3rd level, you can cast the levitate spell once per day. Intelligence is your spellcasting ability for this spell.

Unarmed strikes deal 1d4 + (Intelligence modifier) psychic damage on a hit.

On a succesful hit with your tentacles, if the damage would reduce the creature to 0 hit points, you may choose to kill the target by extracting and devouring its brain.

As an action, you can magically emit psychic energy in a 15-foot cone. Each creature in that line must make a Intelligence saving throw equals 8 + your Intelligence modifier + your proficiency bonus. A creature takes 2d6 psychic damage on a failed save and half as much on a succesfull one. The damage increases to 3d6 at 6th level. 4d6 at 11th level, and 5d6 at 16th level. After you use this ability, you can't use it again until you complete a short or long rest.

You can communicate telepathically with any creature that knows a language within 30 feet.