Circle of Illithid (Mindflayer)

Circle of Brains might be a better description for Mindflayers, as all other lifeforms are beneath them and are considered different quality sources of food.

Brainberry

When you choose this circle at 2nd level, you learn this additional druid spell. It is a spell that requires a piece of fresh brain harvested within the last 24 hours, to cast the spell.

brain repose

When you choose this circle at 2nd level, you learn this additional druid spell, a spell that keeps acquired brains fresh for 10 days.

Circle Spells

3rd hold person, spider climb
5th vampiric touch, slow
7th freedom of movement, stone shape
9th passwall, contagion

natural mucus armor

the mucus covering an illithid body provides +1 to AC

the superior illithid shape

when shape-changing the illithid druid can chose to only partially shape change, keeping the head and feeding tentacles of an illithid, in proportion to the creature its shape changed into.

Tentacle of Shadows

as a bonus action extend facial tentacles additional 5 feet that visually appear as shadows