Thor's Wedding Day: By Thialfi, the goat boy, as told to and translated by Bruce Coville (Magic Carpet Books)

What could possibly make Thor--the massive and mighty god of thunder and protector of all his people--put on a bridal gown? It all begins when the source of Thor's power, his beloved hammer, is stolen. The plan to get it back requires that he dress in fancy finery and be packed off to marry the king of the giants. Luckily, Thialfi, the goat boy, comes along. Working behind the scenes, Thialfi just might save the day . . . which is only fair, because it's his fault the hammer was stolen in the first place.