Hypnos

Hypnos was the personification of sleep, son of Nyx and twin brother of Thanatos. He lived in a dark cave in the underworld where the sun never shone, the entrance surrounded by poppies and other soporific plants. The river Lethe (Forgetfulness) flowed through his domain.

Hypnos was a gentle god who brought rest to mortals and gods alike. No being could resist his power — even Zeus had fallen under his spell. During the Trojan War, Hera persuaded Hypnos to put Zeus to sleep so she could aid the Greeks without his interference. Hypnos was reluctant, remembering Zeus's rage the last time, but agreed when Hera promised him one of the Graces as his bride.

His son Morpheus was the god of dreams, who took the shapes of humans in dreamers' visions. Other sons brought different types of dreams: Phobetor created frightening animal forms, and Phantasos produced inanimate dream images.