This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Menninkainen (Finnish mythology)
In Finnish mythology and lore, a menninkainen is believed to be a leprechaun-like inhabitant of the forests. Fairy tale depictions often involve dominance struggles and favors elicited. Menninkainen were probably originally thought to be spirits of dead people, but folklore about them has changed during time, and they turned to be something else.
They are usually depicted as wearing pointed hats. They are said to be fond of riddles and dancing, and often go hunting for treasure. They are very wary of humans, and live underground, seldom seen on the surface.