Hypnos

In Greek mythology HYPNOS was the god or personified spirit (daimon) of sleep. He dwelt in Erebos, the land of eternal darkness beyond the gates of the rising sun, and rose into the sky each night in the train of his mother Nyx (Night). Hypnos was often paired with his twin brother Thanatos (Peaceful Death), and the Oneiroi (Dreams) were his brothers or sons.
Hypnos was depicted as a young man with wings on his shoulders or brow. His attributes included either a horn of sleep-inducing opium, a poppy-stem, a branch dripping water from the river Lethe (Forgetfulness), or an inverted torch.(source: theoi.com)