Temporal Immunity. The astral barnacle is immune to any time effects.

Aura of Madness. Creatures within 200 feet of the astral barnacles that aren’t aberrations have disadvantage on saving throws and attack rolls.

Creature Sense. The astral barnacles are aware of the presence of creatures within 2 miles of it that have an Intelligence score of 4 or higher. It knows the distance and direction to each creature, as well as each creature’s Intelligence score, but can’t sense anything else about it. A creature protected by a mind blank spell, a nondetection spell, or similar magic can’t be perceived in this manner.

Astral Sense. The astral barnacles are aware the ebb and flow of astral drifts. Any creatures able to communicate with the barnacle benefit from ADVANTAGE when navigating, travelling, or making survival checks in the Astral Plane.

Sharp Chitin. While not able to attack, they have hard chitin exoskeletons that may inflict upto 1d4 piercing damage to anyone slammed against its surface. Spiny tendrils lap up any microorganisms and fleshy flotsam from damaged creatures.