In Irish folklore, Glanconer, meaning "Love-Talker", is the fairy version of Casanova.
Appearance: A tall, dark, and handsome man, with pitch-black eyes who has a love for smoking pipes.
Lore: The Glanconer is an avid womanizer, meeting women in out-of-the-way places, often close to wild nature. As his name suggests, he sweet talks them until they reach the point where they are putty in his hands. His would-be lovers should beware, for most women who succumb to his lustful temptation and sleep with him are usually not long for this world. Like mortal 'love'em-and-leave'em' types, the fairy will abandon his victim after the deed is done. Most of his cast-offs will either go insane and kill themselves or quietly pine away and die. The few that survive will never be satisfied with the touch of a mortal man.
Defense Against A Glanconer: Like all fairies, the Glanconer fears iron objects, salt, and possibly holy objects. The best defense against him is to know fairy-lore. Otherwise self-control is the key to surviving an encounter with the fairy.
Observation: Just as with the Lamia, the Glanconer has a basis in reality, i.e. predatory, womanizing males. The belief in the Glanconer may be be the externalized fear that parents might have concerning their daughters becoming involved with such men.
Good Faeries/Bad Faeries by Brian Froud
Sirens And Other Daemon Lovers