This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Minotaur (Greek mythology)
In Greek mythology, the Minotaur is a mythical creature portrayed during classical antiquity with the head and tail of a bull and the body of a man or, as described by Roman poet Ovid, a being "part man and part bull". He dwelt at the center of the Labyrinth, which was an elaborate maze-like construction designed by the architect Daedalus and his son Icarus, on the command of King Minos of Crete. The Minotaur was eventually killed by the Athenian hero Theseus.
In Crete, the Minotaur was known by the name Asterion, a name shared with Minos's foster-father. "Minotaur" was originally a proper noun in reference to this mythic figure. That is, there was only the one Minotaur. In contrast, the use of "minotaur" as a common noun to refer to members of a generic "species" of bull-headed creatures developed much later, in 20th century fantasy genre fiction.