Katharine Briggs - An encyclopedia of fairies
Hobgoblins, brownies, bogies, and other supernatural creatures
From the Abbey Lubbers (minor devils who were detailed to tempt monks to drunkenness, glutony, and lasciviouness) to "Young Tam Lin" (the most important of the supranatural ballads), An encyclopedia of fairies is a Wonderful companion to the world of make-believe. Spanning ten centuries, this guided tour will enthrall anyone who has ever believed or even half-believed in supranatural creatures.
Mythology - PDF