This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Negret (Catalan)
A negret in Catalan myths and legends, especially those of Majorca, is a small, dark-skinned sprite who, if touched with a candle by a mortal, instantly turns into a trove of coins. The word is the diminutive of the Catalan negre ("black"), and out of this context could mean a small child of a dark-complexioned race.