The constellar are a race of mysterious celestial beings who resemble large humanoid-shaped constellations. During the early ages of the universe, when the titanPantheon brought order to countless planets throughout the Great Dark Beyond, their leader Aman'Thul called upon the constellar to observe the many worlds ordered by the Pantheon. The constellar stayed vigilant for any signs of instability, and, when necessary, initiated a fail-safe procedure to scour a planet of life and reset its evolutionary process.
Unnamed constellar — When the Burning Legion invaded its first world, Sargeras himself annihilated the constellar charged with overseeing the unnamed planet.Aggramar was ordering Draenor at the time and sensed that constellar's death, leading to his confrontation with Sargeras.
Algalon the Observer — Was commissioned by Aman'Thul to serve as Azeroth's celestial guardian. He was later defeated by adventurers as a result of his attempt to reset the planet following rising Old God influence. Since then, he has remained in Ulduar to monitor the activities of Azeroth's mortal races.
Constellar Designates — Appear as adds during the Argus the Unmaker boss fight, after Aman'Thul's attempt to dissipate Argus's weakened physical form by collapsing time around him apparently failed. Each one is vulnerable to a different magic type.
Harbaron, a mysterious ferryman working for Helya, is likely a corrupted constellar. His cloak conceals an expanse of stars (as is conspicuously pointed out in his Adventure Guide), most of his abilities have a cosmic theme, he uses the same animation skeleton as constellar, and his name follows the same pattern as Algalon and Rygelon. [Xal'atath, Blade of the Black Empire] may whisper regarding Harbaron that "it was thought his kind was incorruptible".
According to one legend, the Fist of Ra-den was crafted for Aman'Thul by mysterious celestial beings that reached into Azeroth's sky, took a single bolt of lightning, and shaped it with their hands before giving it to Aman'Thul, who encased it in stone and branded it with titan runes. These creatures may have been constellar.
Constellar may be creatures from the plane of Order, given their orderly nature and arcane-like appearance. Eonar and the other titans also resemble them in their non-corporeal forms, such as when manifesting as the Seat of the Pantheon, further indicating a deeper connection between the Pantheon of Order and the constellar.