A khalkos can infect an intelligent creature with a horrifying disease , injecting khalkos larvae directly into the creature’s skull. While infected with this disease, the host undergoes the following changes:

Telepathy. The host gains telepathy out to a radius of 120 feet. Additionally, the host can telepathically communicate with the khalkos that infected it over any distance, as long as they are on the same plane.

Trust. Whenever a khalkos makes a Charisma check to convince the host of its good intentions, it does so with advantage . If it succeeds, the host becomes friendly to it no matter its previous attitude. 

After 10 (3d6) days, the host develops a splitting headache and is incapacitated for 24 hours. At the end of this time, the host dies. If the host has an alignment trait, 2 or 3 khalkos spawn burst out of the host’s skull after 1 round.

Greater restoration or a similar spell cast with at least a 5th-level spell slot is required to kill the brain larvae and remove the disease.