Limited Telepathy. The cerebrilith can magically transmit simple messages and images to any creature within 120 feet of it that can understand a language. This form of telepathy doesn't allow the receiving creature to telepathically respond.
Multiattack. The Cerebrilith makes three attacks: one with its bite and two with its claws.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 12 (2d8 + 3) piercing damage. If the target is a creature, it must succeed on a DC 15 Constitution saving throw against disease or become poisoned until the disease is cured. Every 24 hours that elapse, the target must repeat the saving throw, reducing its hit point maximum by 5 (1d10) on a failure. The disease is cured on a success. The target dies if the disease reduces its hit point maximum to 0. This reduction to the target's hit point maximum lasts until the disease is cured.
Claw. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 7 (1d8 + 3) slashing damage plus 4 (1d8) piercing damage.
Psionic Blast. Magical Ranged Attack: Wisdom Save DC 18, range 60 ft., one target. Hit: 3d8 + 6 damage, and the target has disadvantage on saving throws until the end of their next turn, miss half damage.