The Dragon Nebula was trigol-type nebula that existed somewhere in the Alpha or Beta Quadrants.
The Dragon Nebula was colonized by human settlers from Earth sometime after the Eugenics Wars. Settling on Pai, these colonists renamed themselves after the same planet, and established a small interstellar nation called the Dragon Empire. The nebula received it moniker due to the distinct shape of a mouth of a dragon. The ionized gases of the nebula, generates considerable interference with ship sensors masking other vessels locations.