A Gancanagh is a male faerie in Irish mythology that is known for seducing human women.
The Gancanagh are thought to have an addictive toxin in their skin that make the humans they seduce literally addicted to them. The women seduced by this type of faerie typically die from the withdrawal, pining away for the Ganacanagh's love or fighting to the death for his love.
The faerie is typically depicted carrying a clay pipe, though he does not smoke it because faeries generally detest smoke.
It is said to have died out or to be the last of its kind.