The Fomorians from Irish mythology are steeped in mystery. It is unknown where they came from, or the length of time they had knowledge of Ireland, and what actually happened to them. Lady Gregory describes one Fomorian habitat as a glass tower in the sea. Many people describe them as sea fairies or sea monsters. My best guess is that they were Nephilim!
Nocnica / Night Hag, in Polish mythology, is a nightmare spirit. She is known to torment children at night. She have a horrible screeching voice, smell of the moss and dirt from her forest. Stone with a hole in the center is a protection from the Nocnica.