From Halopedia, the Halo wiki
Esthetist was the title of a Forerunner individual. The Huragok Prone to Drift mentioned the Esthetist as an example of a Forerunner known by their title alongside the Librarian, Logician, the Master Builder and the Didact when explaining the Forerunners' naming conventions to Jul 'Mdama, who was at the time being held in ONI captivity on Trevelyan.
List of appearances
- Halo: The Thursday War (First mentioned)
- ^ Halo: The Thursday War, page 246