The Satyroi (Satyrs, Fauns) were old fertility spirits that inhabited the wilderness and countryside. They were close to Dionysos, Gaia, Rheia, Hermes and Hephaistos. They were often shown chasing the tribes of Nymphai into the mountains in order to mate with them. In the presence of Dionysos, they would drink and dance, playing instruments of Bacchic orgy, chasing after Nymphai. Appearance wise, they were animal like men who had the tail of a horse, donkey-like ears that pointed skyward, pug noses like a pigs, widdow's peaks and often 'erect members'. (Fertility spirits...).
From the Satyroi come the panes, or fauns. They were more wild than the normal satyr. They were depicted as having hoofed feet, with the ears and horns of a goat atop their heads, or sometimes shown as having a full goat head. These were more closely related to the god, Pan, and as such their name translates into 'All' or 'Pan'. The Paneides were the twelve sons of Pan.Another closely related being that comes from the satyr myth are the seilenoi or Silens. These held the same position as the Satyr, but they were shown as fat, elderly satyrs that were covered in white hair and often had ox horns on their heads. Pheres Lamioi, or the twelve guardians of Dionysos when he was an infant, were most likely Seilenoi.
Far from the warm fuzzy feeling you get when you think of Satyrs, comes the Empousai (Empusae), Mormolykeiai (Mormolyceae) and Lamiai (Lamiae). Empusa meaning 'she who moves on one leg' and lamia meaning 'large shark'.
These share similar traits, as they are depicted as young, beautiful women who would seduce men to bed and then feed on their flesh.The feed on human blood and flesh, often having sharp teeth and pale skin. The guise of a beautiful woman often covered up their true hideous appearances. The Lamiai had serpent tails in place of real legs and the Empousai had hair that was constantly on fire , with one leg of brass and the other of donkey. The Mormolukeiai were thought of as phantoms used to scare small children. Empusa, Lamia, and Mormo were all demigoddesses with separate stories. Empusa was said to be the daughter of Hecate. She seduced young men and would consume them as they slept. She is shown wearing brass slippers with flaming hair. It was said that she could shape-shift into many different forms. Lamia was a beautiful queen that ruled Libya. Some myths describe her as having a serpents tail, though many just describe her as a beautiful woman.It is said that she had an affair with Zeus, and upon hearing this Hera killed Lamia's children. Soon after, crazed with grief, Lamia began hunting down children and devouring them. Mormo was a spirit, often used to frighten children into behaving. From these three come the ideas of Vampires.
Similarly, the Greek's believe in Eidolones, which were Phantoms who possessed the living for a variety of reasons. There are only a few stories that describe what happens to those who are possessed. They are best described as shades or shadows of people. They do not retain who they once were.Sometimes they are considered as 'astral doubles'.
Ovid, Metamorphoses 1. 192 ff (trans. Melville) (Roman epic C1st B.C. to C1st A.D.)
Ovid, Metamorphoses 6. 392 ff
Homeric Hymn IV to Hermes 256 ff (trans. Evelyn-White) (Greek epic C7th to 4th B.C.)