This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Gancanagh (Irish)
A gancanagh (from Irish gean cánach 'love talker') is a male fairy from the mythology of Northern Ireland, known for seducing women. The origins of the Gancanagh lay in Irish and Scottish mythology, legend and folklore. In Ireland, it is known far and wide as a slightly more innocuous, less nocturnal version of the Incubus; in Scotland, though, its exploits seem somewhat more tame.
As the creature is Fay in nature, the Gancanagh is also said to be a relative of the Leprechaun, Clurichaun, Far Darrig, and even the British Redcap. A handsome male fay, the Gancanagh typically has red, brown or black hair (although blond ones are occasionally seen). It is more handsome than the average man, and can often be seen with an unlit wooden smoking pipe in its mouth.