This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Musimon (Heraldic)
The musimon (also known as the tityrus or tytron) is a charge in European heraldry. It is a cross between a goat and a sheep; it has the feet and body of a goat, the head and beard of a ram, and two horns from each for a total of four—two curved and two straight.