This was a DnD adventure I recall playing in the early 90s.
There were three adventures all closely connected: a black dragon, a green dragon (which uses illusions to make itself seem like three dragons together), and a red dragon. There was also a ruined keep filled with squabbling mook races, like goblins, orcs, etc. The dragons had to keep the peace among the tribes, and the lieutenants included a goblin leader and a harpy or siren. Her name was something similar to “Hauraura”.
This would have been 1990 to 1993.