The Oneiroi

The Oneiroi (Ονειροι) were Greek spirits of dreams. They were sometimes said to be the sons of Nyx and, other times, were the sons of Hypnos. They lived in a cave at the edges of the Underworld in Erebus. When emerging from their cave, they passed through one of two gates. One gate was made of horn and gave the spirits prophetic dreams to give to people while the other gate was made of ivory and gave the spirits dreams without meaning. Morpheus was the leader of the Oneiroi. Other dream spirits were Icelus, Phantasus, and possibly Epiales.

In Roman mythology, the Oneiroi were known as the Somnia.