Ikelos, also known as Phobeter, was one of the Oneroi and is the personification of nightmares that appear in various types of dreams. He made shapes of human-like entities appear in dreams.
Ikelos was a son of Nyx. He resided with his brothers, Morpheus and Phantasos in the Underworld. His appearance was that of a daemon, but he appeared in the form of animals and monsters when entering dreams, most commonly a lion or bear.