What does Boxing Day have to do with boxing?
"powerful person," 1670s, from Great Mogul, Mongol emperor of India after the conquest of 1520s, from Persian and Arabic mughal, mughul, alteration of Mongol (q.v.), the Asiatic people.
"elevation on a ski slope," 1961, probably [Barnhart] from Scandinavian (cf. dialectal Norwegian mugje, fem. muga, "a heap, a mound"), or [OED] from southern German dialect mugel in the same sense.
Note: The name “mogul” is sometimes applied to a great personage or magnate. For example, the founders of the major Hollywood studios often have been called “moguls.”